Talk:Challenger Deep/Archive 1

Inconsistencies
The deepest depth listed at the top of the Depth section is 10,923, which is inconsistent with 10,911 listed elsewhere, and 10,911 listed on the Mariana Trench page. I see that the depth is discussed below, but the different numbers for the bottom persist.

Also, according to the heading the Deep was named for a 1951 excursion, but in the body it is stated the "Challenger Deep" had a name in the 1912 encyclopedia. I'm guessing the heading is wrong and had the name earlier, but I don't know this.Daggerot 04:10, 30 May 2007 (UTC)

The HMS Challenger in 1875 originally named the deep they sounded southeast of Guam as the Swire Deep after Herbert Swaire, the ship’s First Navigating Sublieutenant (Corfield, 2003). In Sir John Murray's 1912 book DEPTHS OF THE OCEAN, he used the term Challenger Deep (on page 131), instead of the Swire Deep and applied it to the Nero Deep, reported in 1899 by the US survey vessel Nero (a converted collier). The Nero Deep is 248 nautical miles northeast of the location discovered by the HMS Challenger in 1875, and using the term Challenger Deep for both locations can only be equated to the modern term Mariana Trench, NOT the extreme depression found in 1875. In the 1951/52 survey of the location of HMS Challengers deepest sounding in 1875, the HMS Challenger II called it the "the Marianas Trench between Guam and Ulithi”, in 1951, and called it the Mariana Deep in 1952. Thus the term Challenger Deep used for the location of the 1875 original sounding is of moderen origin and recognizes both ships named Challenger in the discovery of the world's deepest depression. Gwyncann (talk) 06:29, 2 December 2019 (UTC) — Preceding unsigned comment added by Gwyncann (talk contribs) 06:18, 2 December 2019 (UTC) Gwyncann (talk) 06:29, 2 December 2019 (UTC)

In the first paragraph in Section 1, it says that "[t]he maximum surveyed depth of the Challenger Deep is 10,911 m," but the last paragraph in the section gives a depth of 10,924 m.--Eric (talk) 07:52, 5 June 2009 (UTC)

Landforms
Does this qualify under Category:Landforms or what's the alternative? Alren 18:25, 18 Nov 2004 (UTC)
 * Not really. I didn’t see Africa on that list.  This is a point in the bottom of a trench (the Mariana Trench).  The aforementioned trench is there under oceanic trenches.  That list is for things that peninsula, not Florida (e.g. mariana trench) and surely not Miami (e.g. Challenger Deep). Cavebear42 21:46, 18 Nov 2004 (UTC)
 * Should a new category be started for "deeps?" I think they are just as important as the peaks of a mountain range such as Everest or Denali.  Sowelilitokiemu 19:06, 8 January 2006 (UTC)
 * It's neat to see direct conversation on this topic, as the page makes it seem like the information there is all we have. It seems as if the landforms section used to be present on the page, but have since moved to the talk section to be ironed out. I think that a new category for deeps may be useful here, and as we continue to explore the benthic deep, deeps may hide more information that we have not discovered until then. Finkbr (talk) 02:58, 1 March 2023 (UTC)

Depth
How could it be that the deep is "10,911 meters (35,797 feet) deep at its maximum", but "Trieste descended to 10,916 meters (35,813 feet) deep in the trench"? 10,916 is more than 10,911.


 * Yes I would also like to know Reply to David Latapie


 * Okay, let me try to get to the meat of this. there are 3 articels we should be looking at:
 * Bathyscaphe Trieste
 * "she reached a record depth of 35,813 feet"
 * Mariana Trench
 * "The trench has a maximum depth of 35,840 ft"
 * " [Trieste] indicated a depth of 37,800 ft, but this was later revised to 35,800 ft"
 * Challenger Deep
 * "the deepest known point in the oceans, 35,797 feet"
 * "Trieste descended to 35,813 feet deep in the trench"
 * I think that part of the problem is metric - feet convertions messing people up. Part of it is the dates of the measures.  according to Guinness World Records "On January 23, 1960, the US Navy Trieste vessel descended to the bottom of the Pacific Ocean, and on March 24, 1995, the Japanese probe Kaiko recorded a depth of 10,911 m (35,797 ft), the most accurate measurement yet taken.".  Ironicly, accoring to this article from the navy, it was deeper than 37,000 feet. (the only article I could find on the navy site.)  I was the one that put the data in from guinness and didn't mess with the other data from the sourses.  I am open to whomever think that there is a clear way to present this. Cavebear42 23:07, 22 Nov 2004 (UTC)

= Helicopter landing and mountain growing ==::::Let's stay away from meters as that it has never been measured in them. The depth is known and has been measured a few times in differnt methods. weve sent people to the bottom, weve meatured with sonar. im inclined to use guinness as a source and trust its measure (which is well quoted ont he web). Still, we should clean these articles to make them match. Cavebear42 23:46, 22 Nov 2004 (UTC)
 * I've modified this article alongwith Bathyscaphe Trieste with the depth measured by Kaiko. Other articles updated are Jacques Piccard, Don Walsh, and January 23. Jay 11:53, 9 Jun 2005 (UTC)
 * Thought everyone might be interested to know that JAMSTEC'S own KAIKO page lists the depth it achieved at 10,911.4 meters (or 35,798.6 feet). The 35,840 ft number that was floating around comes from the CIA Factbook (take from it what you will). I agree with Sowelilitokiemu's comment below and also believe that a specific number can't be expected.

How much of the difference in measurements is accuracy and how much is actual change in depth? Nature abhors a vacuum, and I'm sure tons of sediment fall into the trench every year. If the subduction slows, I imagine that the Challenger Deep would fill in quite quickly. Sowelilitokiemu 19:01, 8 January 2006 (UTC)


 * Still there´s the question wether Challenger Deep is the deepest known spot in the ocean, which is probably the Vityaz Deep 1 (Mariana Hollow) with - 11.022m. Would be nice to correct that.User:easternsun 0:53, 26 March 2007 (UTC)

Soles and flounders
"They observed small soles and flounders..." I don't suppose this was actually at 10.900 m depth? That's what the article seems to say but I don't know if it is possible. Piet 13:23, 23 January 2006 (UTC)

Allogromids?
A lot of words that I don't understand, and without explanation. Leptohalysis and Reophax are two more. Maybe some of them can be left out and for others a stub/article can be created? Piet 13:28, 23 January 2006 (UTC)

Clarification or edit in Fauna section
''Over the course of six to nine million years, as the Challenger Deep grew to its present depth, many of the species present in the sediment died out or were unable to adapt to the increasing water pressure and changing environment. The remaining species may have been the ancestors of the Challenger Deep's current denizens.''

The sentence in bold seems pretty obvious to me, or perhaps I am reading it incorrectly? The section is describing the unique abundance of soft-shelled organisms in the Challenger Deep compared to other deep-sea survey sites. The last few sentences provide a possible explanation stating basically that the reason is because the current species present adapted to the change. How is this different than evolution in any other corner of the world? That is the premise of evolution, no? The species that adapt to change and survive are able to propagate their lines. The last sentence seems the most (my apologies) "duuh" of all. The current living organisms came from their ancestors... Would anyone think any differently? I mean even to people who believe in "intelligent design" :P

But perhaps I'm missing something obvious, and this section is stating something different? --Acefox 19:50, 9 May 2006 (UTC)

The above sentence also mentions that CHallenger Deep grew to it's present depth over six to nine million years. This is a very short period geologically and it would be a great addition to the article to explain briefly how this happened e.g. are there specific currents that caused erosion of the sea bed, or is it plate tectonics and if so what type of plate movements cause the trench to become deeper?

I disagree that the sentence makes sense as it is. Let's break it down. "The remaining species may have been the ancestors of the Challenger Deep's current denizens." The remaining species (the species currently in the Deep) may have been the ancestors of the Challenger Deep's current denizens (which is insane, because the species currently in the Deep cannot be their own ancestors). I think the author meant for "remaining" to apply to those species that did not die out; (this part of the previous sentence: "...many of the species present in the sediment died out..." and those that did not die out were "remaining.") But that makes "remaining" the modifier of a section of an entirely different sentence, rather than the noun currently following it. It should be changed for clarity sake. 23:47, 21 February 2007 (UTC)~ryanpm

Typhoon
Just a quibble. It says that the cables snapped during a typhoon on March 29, 2003, but there wasn't a typhoon then. There was a tropical storm in January, and a supertyphoon in early April, but nothing in March. Are you sure that date is right? Hurricanehink ( talk ) 02:13, 20 July 2006 (UTC)

HMS Challenger
It seemed odd that there wasn't much info on HMS Challenger, which first surveyed the Challenger Deep. So I've added some info. 86.136.195.43 12:15, 27 January 2007 (UTC)

=the name "Challenger Deep" The first section (which does not appear to be editable) states that "the point is named after the ... survey ship HMS Challenger, which first surveyed the trench in 1951."

This is contradicted by the next sentences which state that the 1910 Murray book calls the location surveyed by the H.M.S. Challenger in 1875 the Challenger Deep. This fact is true, based on the citation of the page on which the statement occurs.

Therefore, the (uneditable) lead to the discussion should read: "The point is named after the British steam corvette HMS Challenger, which discovered the deep in 1875. The first survey of the Marianas Trench which includes the Challenger Deep at its southern extremity, was fittingly made by Challenger's namesake, the British Royal Navy survey ship,HMS Challenger. —The preceding unsigned comment was added by Hmschallenger (talk • contribs) 18:29, 10 April 2007 (UTC).

Not really. The HMS Challenger in 1875 originally named the deep they sounded southeast of Guam as the Swire Deep after Herbert Swaire, the ship’s First Navigating Sublieutenant (Corfield, 2003). In Sir John Murray's 1912 book DEPTHS OF THE OCEAN, he used the term Challenger Deep (on page 131), instead of the Swire Deep and applied it to the Nero Deep, reported in 1899 by the US survey vessel Nero (a converted collier). The Nero Deep is 248 nautical miles northeast of the location discovered by the HMS Challenger in 1875, and using the term Challenger Deep for both locations can only be equated to the modern term Mariana Trench, NOT the extreme depression found in 1875. In the 1951/52 survey of the location of HMS Challengers deepest sounding in 1875, the HMS Challenger II called it the "the Marianas Trench between Guam and Ulithi”, in 1951, and called it the Mariana Deep in 1952. Thus the term Challenger Deep used for the location of the 1875 original sounding is of moderen origin and recognizes both ships named Challenger in the discovery of the world's deepest depression. Gwyncann (talk) 06:29, 2 December 2019 (UTC) — Preceding unsigned comment added by Gwyncann (talk contribs) 06:18, 2 December 2019 (UTC) Gwyncann (talk) 06:29, 2 December 2019 (UTC)Gwyncann (talk) 06:37, 2 December 2019 (UTC)

The picture is inaccurate
The picture comparing the depth of the Challenger Deep and Mount Everest is inaccurate. The scale on the right of the image shows the depth of the Challenger deep to be 12,00 feet when it is in fact 10,924 meters at the maximum measured depth. The picture should either be updated (with better graphics if possible) or removed. —Preceding unsigned comment added by Barhamd (talk • contribs) 06:09, 3 June 2009 (UTC)

Also - this picture is totally misleading and factually wrong. The scales are COMPLETELY different. The picture shows the Everest massif - which is only 3500 meters tall, as being over 8000 meters tall! This picture should be removed, or the height of the tibetan plateau added to the diagram to again make it accurate. Bassclef (talk) 09:21, 3 June 2009 (UTC)

Number of descents?
If only 3 descents have been achieved (1960, 1995 and 2009), how can Nereus be the first vehicle to reach it "since 1998"? --Markmcrobie (talk) 08:57, 3 June 2009 (UTC)
 * I don't know. Please ask the BBC. :) -- can  dle &bull; wicke  13:50, 3 June 2009 (UTC)
 * Note that it says: "Nereus thus became the first vehicle to reach the Mariana Trench since 1998" and not that it was the first to reach Challenger Deep. Thus it can be assumed that there was an expedition to the Mariana Trench in 1998 (the last to reach it until now) which didn't go to the Deep - Dumelow (talk) 21:15, 4 June 2009 (UTC)

Which expedition?

 * Murray was one of the expedition scientists, a young man at the time

This part refers to an expedition that isn't named that I could see. I couldn't immediately find it in the reference, although I imagine if I had the time to scout backwards a while it should be there somewhere. --86.139.65.151 (talk) 14:48, 5 June 2009 (UTC)

Merge to Mariana Trench?
I find it quite strange that this article isn't just a part of Mariana Trench, especially considering that the summit of Everest doesn't have it's own page. What about Challenger Deep merits a separate article that no "highest point" does? I assume it's because "highest" point is slightly more subjective (Chimborazo and whatnot), while this is unequivocally the lowest point (closest to the Earth's core), but still, I question the separate article status.98.239.166.251 (talk) 20:59, 22 July 2009 (UTC)
 * Mount Everest is a particularly high spot on the Himalaya range, and is thus given its own name like other high spots (we call them mountain peaks), and this is usually defined by the highest it gets. How do you decide to give something a name of its own? Do mountains exist objectively, or do you create them in your imagination as separate objects, due to hosting local points of interest?  The more proper metaphor I think is that these deeps are like peaks, inverted, in a mountain chain, which is the trench. There are actually several deeps within the Mariana Trench (which is like an inverted mountain range), all of which are considerably deeper than the average trench floor depth, and the Challenger deep is merely the deepest, and thus the only one that has its own Wiki article. But there are many named "Deeps," within named trenches, in several oceans.   S  B Harris 00:00, 23 July 2009 (UTC)

Unnecessary repetition in the introduction
"Thus, the Challenger Deep is a relatively small slot-shaped depression in the bottom of a considerably larger crescent-shaped trench, which itself is an unusually deep feature in the ocean floor."

Is this sentence really necessary. Its basically just paraphrasing what was JUST said, only cutting out the relevant details. While I would argue that it is good to make information clear to anyone with a pulse, I think the above sentences are hardly technical, and anyone who cares to make the effort can figure it out in about 10 seconds without the aid of the quoted bit. --Pstanton (talk) 00:41, 6 October 2009 (UTC)

Comparative picture
A picture comparing the depth of the Challenger Deep with more graspable objects would be useful and add much value to the article.

http://i.imgur.com/m3ZxZ.jpg is good but of unknown copyright status. —Preceding unsigned comment added by 90.230.133.224 (talk) 02:24, 14 February 2010 (UTC)

Geographic proximity
Is it just me, or is it a bit strange that the intro paragraph says Challenger Deep is near the Mariana Islands, but then the closest island listed (Yap) is really part of FS Micronesia? Add to this that it's on the other side of Guam from the Northern Mariana Islands; and while Guam is part of the Mariana archipelago, it's not part of the group which name includes "Mariana". Maybe the location instead of referencing the "Mariana Islands" should say that it's at the southern end of the Mariana Trench, southwest of Guam? --Hooperswim (talk) 02:51, 7 August 2010 (UTC)

Proposed Future Dives
Hollywood film director James Cameron is preparing to dive to the bottom of Challenger Deep, it was revealed Sunday September 12, 2010. An Australian Company has been commissioned to build a deep sea submersible which can reach the bottom of the Mariana Trench. By latest news reports the company has been working on the project for sometime and expect completion by the end of 2010. Actual filming in the trench for the movie with a tentative release date of 2014 should start early next year. Shieldwolf (talk) 12:46, 12 September 2010 (UTC)

Removed possible nuclear waste disposal site section
Moving this from the main page, as it has many problem, least of all the sourcing. Viriditas (talk) 11:23, 17 September 2010 (UTC) "Like other oceanic trenches, the Challenger Deep has been proposed as being a site for nuclear waste disposal. Being a fast-moving subduction plate, the place has been considered numerous times, as the nuclear waste would theoretically be pushed into the Earth's mantle."
 * What do you think of the new source?  Fell Gleaming talk  11:39, 17 September 2010 (UTC)
 * The material was moved to the talk page for discussion, not for you to revert it back in and then discuss. I am going to be removing the material again until we have consensus here on the talk page for adding it back in.  The source you added is not a RS for science articles.  You are welcome to use the discussion page to talk about it. Viriditas (talk) 11:41, 17 September 2010 (UTC)
 * I'm sorry, but this is contrary to WP Policy. When a significant change such as yours is reverted, the proper behaviour is not to again remove it, but to first seek consensus for the controversial change.  Furthermore, the Helium source is not being used as a WP:RS for a science claim, but merely to support that the location has been suggested as a waste repository.  The subduction claim is science, and that still needs to be supported.   Finally, your removal claims that the text has 'many problems', but you cite only one.   I ask that you self-revert your change and first attempt to seek consensus.   Fell Gleaming talk  11:47, 17 September 2010 (UTC)
 * No, I'm sorry, as I'm afraid you gravely misunderstand Wikipedia policy and how Wikipedia articles are written. Per WP:V, "Any material challenged or likely to be challenged, and all quotations, must be attributed to a reliable, published source using an inline citation....Anything that requires but lacks a source may be removed..."  You should right now, be hunting for reliable sources, not edit warring over poorly sourced and inaccurate material.  Please use the talk page to discuss how we can best rewrite this material with good sources.  What you are not supposed to do is keep adding the disputed material back into the article with bad sources.  Please take a moment to think about this. Viriditas (talk) 11:55, 17 September 2010 (UTC)

Edit: Here is another source that supports the location was considered as a potential dumping site:. And here is another source that validates the subduction zone claim:. Fell Gleaming talk 11:52, 17 September 2010 (UTC)
 * Are either of those sources reliable? Science articles generally require books, scholarly articles, and high quality news sources that are reviewed by editors.  Please slow down and do a little bit of research.  I am trying to help, but I keep getting distracted by the reverts and the accusations.  Viriditas (talk) 11:54, 17 September 2010 (UTC)
 * I just looked at both of the sources you provided. Neither meet the requirements for WP:RS. Please take a minute and slow down.  Understand that we will get this information back in the article with good sources.  There is no hurry.  Now, I would recommend starting with Google books and scholar, as that is the easiest place to find good sources.  If you don't want to do that, then please take a break and let me do it. Viriditas (talk) 11:57, 17 September 2010 (UTC)

Fell, I just looked at the page history and saw this edit you made. Your edit summary says you removed the material because it was "not in source." However, putting aside the quality of the material or the source for the moment, the information you removed was referred to by the source, however indirectly: "The discovery of living organisms at such a depth was to prove an important argument against dumping nuclear waste in ocean trenches." The source is talking about Challenger Deep, and the argument against dumping nuclear waste in ocean trenches refers to the United Nations Convention on the Law of the Sea. I agree that the source is not very good and the material was poorly written, but it is accurate. Now, why would you remove this poorly sourced material, but keep poorly sourced material proposing the site for nuclear waste disposal, when you know that it is already banned? Could you explain this? Viriditas (talk) 12:16, 17 September 2010 (UTC)
 * Fell, here is a good source that supports both claims:
 * "In general, Pu in glass or ceramic logs can be placed into a geological repository...it could be deposited in very deep ocean trenches, such as the Challenger Deep. The Challenger Deep is 11-km deep and slowly subducts into the Earth. This is technically sound but it violates the treaty that bans ocean dumping."
 * Please note that the source describes the plate as slow, not fast, and makes it clear that the dumping is banned. Viriditas (talk) 12:25, 17 September 2010 (UTC)

(ec) : The claim I removed was not 'poorly' sourced, it's not sourced at all. The Guardian article merely says the dive was an "important argument against" dumping. It says nothing about international law, or who may or may not have ratified it. I don't dispute the claim itself, but I merely haven't had time to locate an alternate source. As for the World Nuclear Association source, it is as reliable a source as any international organization, and has been used as one for numerous other articles. Fell Gleaming talk 12:30, 17 September 2010 (UTC)
 * Fell, I just explained how it was sourced above. The "important argument against dumping nuclear waste" helped provide a basis for the United Nations Convention on the Law of the Sea.  This is not in dispute by anyone.  I'm sorry if this is confusing for you. In any case, we now have a good source.  Here is the template:

""


 * Based on that source, I think it is acceptable to link to the United Nations Convention on the Law of the Sea. Viriditas (talk) 12:37, 17 September 2010 (UTC)
 * Viriditas, I'm sorry but you're still confused. If an article claims "an international treaty bans nuclear dumping, it is unacceptable to support that with a newspaper article that simply says a dive was an "important argument" against dumping.  The one in no way supports the other.   The claim itself may be true, but as it stood it was uncited, and needed to be addressed.   Do you understand now?   Fell Gleaming talk  12:50, 17 September 2010 (UTC)


 * addendum. Your source is good.  Here's another, that specifically identifies the treaty, and also point out that the US and Russia (the two nations most involved) are not bound by it.      Fell Gleaming talk  12:34, 17 September 2010 (UTC)
 * You'll need to find a better source. The website for the "Law of the Sea Institute" isn't a great fit.  You seem to enjoy adding and removing claims you personally agree or disagree with, and relying on self-published websites to support your views, rather than letting good sources speak for themselves.  Try to write from the POV of the topic, rather than your own beliefs on the subject.  Unless you have a source saying that the U.S. and Russia aren't bound to the treaty in relation the subject of dumping nuclear waste in the Challenger Deep, you are pushing a POV that is above and beyond the sources in use.  Please remember, when we use a source, we don't dress it up with coats or synthesize it with material beyond the subject matter.  Unless there is a reason to specify that a certain nation isn't bound to a certain treaty, we don't say that.  Of course, if a source says that in direct relation to this topic, by all means, add it.  Stick only to the sources about the topic, and the material they contain, nothing more, nothing less. Viriditas (talk) 12:42, 17 September 2010 (UTC)
 * Why don't you follow policy and WP:AGF? Further, I can't understand what possible objection you would have to a Berkeley University Law website, for a source on international law.  The article in question is specifically about international law where it relates to nuclear dumping.   Can you explain your reasoning here?   Still further, I'm as unclear on what "POV" you believe me to be pushing.    It rather seems like your arguments are degenerating into an WP:IDONTLIKEIT appeal against the topic itself.  12:47, 17 September 2010 (UTC)
 * Fell, I get the sense that you aren't reading my replies. Does the self-published Law of the Sea Institute website mention the topic of "Challenger Deep"?  Yes or no, please. Viriditas (talk) 12:54, 17 September 2010 (UTC)

Viriditas, you're rather badly misunderstanding Wikipedia policy on synthesis. As example, if an article claims "this book was written by John Smith, who died in 1981", and you cite a newspaper obituary to verify the 1981 portion of the claim, that source in no way, shape, or form has to specifically mention the subject of the article. If you doubt this, I suggest you post for clarification to Wikipedia's original research noticeboard, where a number of editors will be happy to set you straight. Using multiple independent sources is the very heart of what an editor should be doing. Synthesis only comes when you combine those disparate sources to reach a conclusion not supported by any of them.

In the meantime, we have a number of sources that verify the original text. If you want to suggest an alternate rewording before its reinserted, please do so now. Fell Gleaming talk 13:01, 17 September 2010 (UTC)
 * Fell, I haven't misunderstood a thing, and as you have been repeatedly reminded, you cannot use sources that have nothing to do with the topic. This topic is about the Challenger Deep.  The source you want to use, a self-published Law of the Sea Institute website, says nothing about Challenger Deep.  Please don't continue to misuse sources in a way that promotes your personal POV.  That is OR and synthesis, and you are advancing a POV that is not connected to the topic.  I'm sorry you are having great difficulty understanding this fact, but that is the way it is, and that is the way Wikipedia works.  You are certainly welcome to closely parphrase the Hafemeister material, but you are not allowed to use sources outside this topic to push your POV.  If this isn't making sense to you, feel free to ask someone on one of the noticeboards, such as the RS or NOR noticeboard, for guidance and help.  Viriditas (talk) 13:06, 17 September 2010 (UTC)
 * This battleground mentality of yours has to stop. A Berkeley Law site is an excellent source for international law.  It specifically mentions treaty obligations vis a vis nuclear dumping at sea.  The objection that, since it doesn't name this specific location on the world's seas is, frankly, ludicrous.  Challenger Deep is a portion of the world's oceans; it is covered quite clearly.   If you don't suggest an alternate rewording,  I'll simply reinsert the original text, sourced via the new citations.   Fell Gleaming talk  13:15, 17 September 2010 (UTC)
 * Fell, if you keep disrupting this talk page, you could be blocked for your bad behavior. We write articles from sources about the topic.  We don't take disparate sources from here and there that have nothing to do with the topic and combine them with other sources that do, and we certainly don't do it to push a POV or to make a point like you are doing.  You're engaging in OR, synthesis, and just plain bad editing.  Now, listen carefully: You've got the Hafemeister material.  It discusses this topic, in addition to the nuclear issue, and the ban.  That's it.  Understand?  If you don't understand, then you will need to find someone else to explain it to you, because I have already done so several times.  Now stop disrupting this article with your tendentious edits.  We only use sources about the topic.  End of discussion.  If you don't like it, then you'll have to change the policies and guidelines.  Good luck. Viriditas (talk) 13:22, 17 September 2010 (UTC)

The alternate rewording has been inserted, along with an additional citation on plate subduction. Fell Gleaming talk 22:43, 17 September 2010 (UTC)
 * The disputed wording and source has been removed pending the outcome of this discussion and the noticeboard report. I'm a bit confused why you added unformatted references to the article after I formatted them for you above.  Please try to help improve this article. Viriditas (talk) 01:43, 18 September 2010 (UTC)
 * For the record, please state clearly your objection to the text. Do you or do not you not believe the US has not ratified UNCLOSIII?  Wikipedia even has an entire article on the US's failure to ratify.  Are you seriously claiming there's a verification issue with this point?  Here's another newspaper article on the subject: .  And another article, this time from the NY Times: .  Here's an entire website setup on the issue: .  You're far into the Twilight Zone on this point.  I suggest you step back and rethink your position carefully.  Fell Gleaming talk  01:55, 18 September 2010 (UTC)
 * In addition to not understanding how we use sources, you appear to not understand the editorial burden of truth. You need to show that sources about the Challenger Deep discuss this subject, and you need to explain why it is important to claim that the U.S. has not ratified the international treaty in this article.  The U.S. overwhelmingly supports ratification and honors the treaty.  Why are you adding this to the article when the relevant point in the relevant sources on this topic only concerns itself with the fact that using the Challenger Deep as a dumping ground "violates the treaty that bans ocean dumping"?  That's the only thing that needs to be said.  What good reason do you have to add non-Challenger Deep sources that talk about the ratification? This article is not about the ratification of the international treaty.  Is this making sense to you? Now, you and I both know why you keep adding it.  You keep adding it because this is the number one conservative talking point straight from the office of Jim Inhofe (R-OK) and conservative, right-wing think tanks who as a very vocal minority, oppose the treaty (contrary to the strong support for ratification by the majority of the U.S. government since 1982) because they feel it will threaten the sovereignty of U.S. coastal waters and open the U.S. up to international climate change restrictions and lawsuits.  Of course, none of that has anything to do with this article, but you keep adding it as a POV commentary on the treaty, a minority, albeit fringe commentary that has no place in this article at all.  Your contribution history shows that you keep doing this on article after article.  You're going to need to stop what you are doing, and hunker down and learn how we use sources.  Unless the source is about the Challenger Deep, it isn't relevant.  And your attempt to use this article to push a fringe POV that is at odds with the overwhelming support by the U.S. government, the Navy, and every ocean organization, is hereby noted. Viriditas (talk) 02:09, 18 September 2010 (UTC)
 * "You need to show that sources about the Challenger Deep discuss this subject" I'm sorry, but this couldn't be more wrong. WP:V requires the material in question be verified by a source. It doesn't require that every source also specifically mention the article subject.  It merely has to verify the statement in question.  This is really rather basic.   Fell Gleaming talk  02:23, 18 September 2010 (UTC)
 * WP:V says that the source "must clearly support the material as presented in the article." Identifying reliable sources is explicitly clear on how we use sources: "Sources should directly support the information as it is presented in an article, and should be appropriate to the claims made." WP:SYN is also clear: "Do not combine material from multiple sources to reach or imply a conclusion not explicitly stated by any of the sources."  You have not provided a source that says that the U.S. supports dumping nuclear waste in the Challenger Deep against the international treaty that they in fact, support and honor.  This is what your edit implies, among other things.  This article is not about who supports the international ban on ocean dumping.  If it was, I could cite source after source, showing the vast majority of the U.S. population, government, military, ocean organizations, and businesses support the ban.  I could also show that ratification has been held up by the efforts of several Republican Senators like Jim Inhofe, while numerous Presidents and administrations since 1982 have supported it.  But, that's not the topic of this article.  Capische?  You need to stick to what the sources say about the topic, and you need to stop POV pushing.  This article is about Challenger Deep.  If you can't agree to use appropriate sources about the nuclear disposal proposal, then the section shouldn't even be here.  You're already giving it undue weight with your focus on this topic.  Find more sources that support your position. Viriditas (talk) 02:42, 18 September 2010 (UTC)

"You have not provided a source that says that the U.S. supports dumping nuclear waste in the Challenger Deep" For the simple reason that the text doesn't state that. It's not true. Are you even reading edits before you revert them. The text you removed was "As of September 2010, the US has not ratified this treaty". How you got from that to "the US supports dumping", I have no idea. It's not stated. It's not even implied. I note from your referring to "Republican Senators" that you appear to be politicizing what is in fact a very simple statement. The reader can draw their own conclusions from the facts. The facts themselves are verified, and by reliable sources. Fell Gleaming talk 02:46, 18 September 2010 (UTC)
 * Why did you add "as of September 2010, the US has not ratified this treaty"? How is whether the U.S. has ratified this treaty or not relevant to this article? We already know that the U.S. supports and honors it.  Could you explain why you keep introducing political commentary into this article where none appears in the original source about the Challenger Deep?  Please answer this question.  That's not how we write articles or how we use sources. Viriditas (talk) 02:58, 18 September 2010 (UTC)
 * That is not synthasis, the source does say the US has not ratfified it. As to why its relevant, why is it not?Slatersteven (talk) 12:40, 18 September 2010 (UTC)
 * It is synthesis, and the source, Hafemeister (2007) supporting the central thesis, says nothing about ratification. The burden for relevancy rests on the editor adding content, not removing it.  We don't ask, "why is it not", we ask why it is.  Having been active since 2007, you should know this, Steven.  WP:BURDEN, etc. Viriditas (talk) 12:45, 18 September 2010 (UTC)
 * You have a highly flawed interpretation of synthesis. The US has not ratified the treaty, period.  You may not like that fact, but its a fact, and a well-verified one.  Your "central source" is a book by a physics professor, who is not an authoritative source on international law. (Even worse is the fact there is no conflict between the two source, except in your head)  Fell Gleaming talk  12:54, 18 September 2010 (UTC)
 * Fell, you're a bit confused. The "source" is yours, and I found it for you because you were unable to determine what a reliable source is, remember?  You are welcome to find another one, if you can. Criticizing me for helping you is a bit odd.  Whether or not the U.S. has ratified a treaty, has nothing to do with this topic.  The only reason you keep introducing it here and in other articles, is because it is a political talking point that has several implicit assumptions (as detailed on the NOR noticeboard by myself and another editor) that are not connected with this topic.  In other words, you are POV pushing, again.  Please stick to the topic of this article, and only use sources that discuss this topic.  We already have an article on the topic of the United States non-ratification of the UNCLOS.  This, however, is not it. Viriditas (talk) 13:15, 18 September 2010 (UTC)


 * Sources for non-ratification
 * http://books.google.co.uk/books?id=mRIrrVsULXwC&pg=PA393&dq=UNCLOS+III+%2B+us+non+ratification&hl=en&ei=QbaUTLLTJorKswaftfFa&sa=X&oi=book_result&ct=result&resnum=4&ved=0CDkQ6AEwAw#v=onepage&q=UNCLOS%20III%20%2B%20us%20non%20ratification&f=false
 * http://books.google.co.uk/books?id=DfixUsnDftkC&pg=PA230&dq=UNCLOS+III+%2B+us+non+ratification&hl=en&ei=yraUTMfmKc2RswaS3KRk&sa=X&oi=book_result&ct=result&resnum=6&ved=0CEEQ6AEwBQ#v=onepage&q&f=false
 * http://books.google.co.uk/books?id=DJCnZlJVf9oC&pg=PA62&dq=UNCLOS+III+%2B+us+non+ratification&hl=en&ei=MLeUTK3_BNHLswaN0_Vk&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDYQ6AEwAjgK#v=onepage&q&f=false Actually says non participation, but does show that the US does not accept the treaty obligations.
 * There may well be others (in fact there are).Slatersteven (talk) 13:05, 18 September 2010 (UTC)
 * You're still a little bit confused, Steven. What does those sources have to do with this topic?  We already have an article on United States non-ratification of the UNCLOS.  However, this isn't it. Viriditas (talk) 13:13, 18 September 2010 (UTC)
 * Well the US has said that dumping i nt eh deep is a really good idea (we have sources for that, that a un treaty wants to make it illegal (we have sources for that), and that the US refuese to ratfiy the treaty becasue of the very clause (though they have not stated (and neitehr do we) that the reason is nuclear dumping) that would make the dumpijng illegal. I would say that makes it relevant to the section. Now if the section as a wholes is removed that might be a different matter. But to imply that dumoping of nuclear waste in the trench has been banned 9and that ban acepted) by all countries is also OR.Slatersteven (talk) 13:47, 18 September 2010 (UTC)

Multiple people have explained it to you many time, Viriditas. What's ironic is your sole objection to the statement comes from your fear that someone who knows the facts will suddenly think, "hey, nuclear dumping is a good idea!" when the reality is they'll actually respond, "hey, the US should ratify the treaty!". In any case, that's irrelevant. Our job as editors is to present the facts to the reader in a neutral, unbiased manner, not whitewash out facts we personally find objectionable. Fell Gleaming talk 13:40, 18 September 2010 (UTC)
 * On the contrary, FellGleaming, you've ignored the explanations from multiple editors, both here and on the OR noticeboard. Until you show that you understand how we use sources, you will not be able to add your content.  You have not done the most basic research on this topic, nor have you found reliable sources that show it is a significant aspect of the subject and proportionally represented in the sources. Viriditas (talk) 00:00, 20 September 2010 (UTC)

"Navel of the World"
The significance of noting US non-ratification is, of course, the fact that the US generates more nuclear waste than any other nation in the world. Fell Gleaming talk 14:57, 18 September 2010 (UTC)
 * That is completely irrelevant so long as they are not planning to dump it into Challenger Deep. If you have a reliable source that the US is planning to do that, please provide it. But I doubt it, since apparently it's only a small minority of politicians that is blocking ratification of the treaty. Hans Adler 15:04, 18 September 2010 (UTC)
 * That's a rather unusual interpretation. In a section on nuclear waste dumping, the fact that the largest source of that waste isn't legally barred from dumping is most certainly relevant, whether or not they have any active plans to do so at this time.   Fell Gleaming talk  15:07, 18 September 2010 (UTC)
 * Since there is a treaty against this dumping and nobody has ever done it, the section is only barely noteworthy anyway. I am getting the impression that you may be trying to abuse this article of an international encyclopedia, about an international topic, for advocacy related to American interior politics. Hans Adler 15:12, 18 September 2010 (UTC)
 * And I'm getting the impression you're so emotionally horrified by the mere thought dumping that you're trying to censor notable and well-sourced material because you just don't like it. The fact that this trench has been proposed many times as a waste dump is certainly an interesting and notable fact.  The fact that it is barred by international treaty is also interesting.  And the fact that the US -- the largest producer of nuclear waste -- has continually refused to ratify that treaty is also both interesting, relevant, and well sourced.   Fell Gleaming <sup style="color:black;">talk  15:16, 18 September 2010 (UTC)
 * Can you please provide a reliable source for the claim that "the US" as opposed to a few politicians inside the US, have "refused" to ratify the treaty? Thank you. Hans Adler 15:31, 18 September 2010 (UTC)

Anyway, I think I have found a simple way out: Let's just say the following:
 * however a small number of UN members (e.g. X, Y, Z) have not signed or not ratified the treaty.

Where X, Y, Z are the most populous UN members that have not signed or not ratified, in descending order of population size. I am sure that will include the US. Hans Adler 15:31, 18 September 2010 (UTC)
 * I think that's more than fair. Anyone else object?   Fell Gleaming <sup style="color:black;">talk  15:33, 18 September 2010 (UTC)

I do. Please note that FellGleaming's Berkeley source states that the major legal constraint here is not the Law of the Sea Treaty, but the London Convention, which the US has ratified, and which, by 1993 amendment bans the dumping of nuclear waste. See [this post for further details.--[[User:Slp1|Slp1]] (talk) 16:29, 18 September 2010 (UTC)
 * The United States is not party to the London Convention. See here  for a list of all signatory states.  The United States Law MPRSA prohibits dumping of nuclear wastes -- but only in US Territorial Waters.   Fell Gleaming <sup style="color:black;">talk  16:46, 18 September 2010 (UTC)
 * I guess you missed the United States on page 3 of the appendix. Slp1 (talk) 17:18, 18 September 2010 (UTC)
 * Read the entire source. It is the later Protocol that bans all dumping, and there are only 38 signatories to that portion:     Fell Gleaming <sup style="color:black;">talk  17:32, 18 September 2010 (UTC)
 * Sorry you are just plum wrong. It is disturbing to see you make these kinds of claims.  See   It is the 1993 amendment that bans the dumping of radioactive waste.  The 1996 Protocol mentions nothing about radioactivity, nuclear waste etc at all. --Slp1 (talk) 18:06, 18 September 2010 (UTC)
 * I don't see that link stating that all nuclear dumping was banned in 1993.  Can you highlight the text you're looking at?  Fell Gleaming <sup style="color:black;">talk  18:15, 18 September 2010 (UTC)
 * Howabout "A decade later in 1993, the delegates to the sixteenth meeting of the LDC made the ban on the dumping of nuclear material at sea formal, permanent, and binding" from the Berkeley article you yourself proposed.. Or "In November of that year the London Convention added an amendment prohibiting the dumping of nuclear waste at sea," or The United States and 36 other nations voted Friday to permanently bar the dumping of nuclear waste at sea. Why ask question when it was already at your figure tips and so easy to find? Slp1 (talk) 18:28, 18 September 2010 (UTC)
 * By your last source, it says the US voted for the ban -- but the Britain, France, Russia, and China all abstained. So you feel  that's the text which should go into the article?  Fell Gleaming <sup style="color:black;">talk  18:34, 18 September 2010 (UTC)
 * Well, we could, if it wasn't synthesis to do so. And if it wasn't out of date too, since, according to the IMO, with Russia accepting the amendment the "prohibition of the disposal of radioactive wastes at sea is finally in force for all Contracting Parties to the London Convention"- this includes all of the countries you mentioned, so I guess they had a change of heart.
 * It's fine and accurate to say that nuclear dumping is banned by international law, as Viridatis had it. The fact that the very source you propose states that the deep sea dumping "is forbidden by international law", that with the 1993 amendment of the London Convention "the ban on the dumping of nuclear material at sea formal, permanent, and binding", and that the UNLOSIII treaty is only weakly related to the issue ("has some provisions that can be interpreted as applying to subseabed disposal") suggests that mention in this article of the US's failure (to date) to ratify this second treaty is inappropriate per WP:UNDUE, WP:SYNTH and likely WP:NPOV.  --Slp1 (talk) 19:03, 18 September 2010 (UTC)
 * Also it does not say they have ratified it, it says they have either ratified it or agreed to its implimentation (but without ratificatio it would not apply to the USA). The source does not specifiy which if these it is.Slatersteven (talk) 17:43, 18 September 2010 (UTC)
 * Give it up. They ratified the London Convention.--Slp1 (talk) 18:06, 18 September 2010 (UTC)
 * I don't see that source either stating that the original 1972 London Convention banned all dumping of nuclear waste. Fell Gleaming <sup style="color:black;">talk  18:17, 18 September 2010 (UTC)

It appears that FellGleaming is right about this point as far as low-level radioactive waste is concerned. The US ratified the London Dumping Convention of 1972 but, as of the writing of the Berkeley document had not ratified either the 1993 amendment that also banned low-level radioactive waste, or the 1996 revised convention which bans the dumping of all radioactive waste implicitly by giving a positive list of what may be dumped. It clearly says so in the Berkeley document. From the IMO website one can download a spreadsheet showing country/ratification status for many conventions. It was last updated a few days ago. It confirms that the US still hasn't ratified the 1996 revised convention. (Theoretically the US could still have ratified the 1993 amendment since 2004, but that seems unlikely.)

Of course, if we really want to keep this section about dumping in the article, then we need to make sure that it is NPOV. I find it hard to believe that "technically feasible" is an adequate description for dumping radioactive waste into a depth of 11 km, i.e. a pressure of more than 1000 atmospheres. Whatever container you use is bound to burst rather soon (certainly long before the topic subduction even becomes relevant, so that should probably be removed as a red herring), and surely this obvious fact is reflected in the technical literature. (Maybe I am even wrong, but then surely the experts will have discussed why.) I confess that by now I trust FellGleaming to be unusually well informed about this topic (and about some things surrounding global warming), but that I do not trust the user to tell us the full truth about such things. Hans Adler 21:24, 18 September 2010 (UTC)


 * You vitrify the material first. There is no container to burst...and even were it in a container that did burst, where would it go?  The waste is typically far denser than steel; saying it sinks like a stone is an understatement.   And I appreciate the (mostly) kind words.  By the way, if you are interested in the topic, you might be curious to find out that the entire history of nuclear waste dumping (including Russia's gargantuan degree of dumping HLW and decommissioned reactor cores, often into shallow coastal waters with no protective steps whatsoever), only increased the radioactive background of the world's ocean by 1/3000 of the amount that atmospheric testing did during the 1950s-60s -- and 1/3,000,000 of the normal background radiation level already within the ocean.  Furthermore, continued dumping at those levels would not have appreciably raised levels much further, as the increase was due primarily to short-life daughter nuclides such as Cs-137, I-131, etc, which decay much faster than the uranium, thorium, and radium found naturally in sea water.  During discussions of the dumping ban, even the IMO itself admitted the ban was about "social and political" reasons, rather than for scientifically justified reasons.   A discussion at this level is, of course, far beyond this particular article's aegis.   But the fact remains that dumping the material into a subduction zone isn't really necessary at all   Fell Gleaming <sup style="color:black;">talk  21:42, 18 September 2010 (UTC)
 * Hi Hans. I'm afraid that FellGleaming is not as well informed as you might think.
 * The 1993 amendment refers to low-level radiation because higher radiation levels werealready banned.see this and this and "The prohibition of dumping high-level radioactive wastes, in force since 1975, was extended in 1993 to cover all radioactive wastes, through the adoption of Resolution LC.51(16)".
 * When you amend a treaty, the treaty does not need to be re ratified, and in this case the US voted for it as we know. The IMO announced in 2005 that "prohibition of the disposal of radioactive wastes at sea is finally in force for all Contracting Parties to the London Convention". I think if you check again the spreadsheet doesn't have a column for the LC for 1993, because it simply isn't needed.... they amended the original convention.
 * The London Protocol replaces the London Convention for those who ratify it, but the London Convention remains in force for those who haven't. "The 1996 London Protocol to the London Convention came into force in March 2006 and supersedes the Convention for the contracting parties. There are presently 26 such parties including many European countries,  Australia, Canada, and Mexico — but not the United States, which remains bound by the London Convention.--Slp1 (talk) 22:06, 18 September 2010 (UTC)

OK, good points by both of you, so apparently things are a bit more complicated:
 * To judge from the ratification state of various conventions, the US (having ratified only the original London Convention) is theoretically still free to dump low-level radioactive waste but not high-level radioactive waste. – If that is not true I am sure FellGleaming is going to tell us why not.
 * According to an OECD report from 1999, Geological Disposal of Radioactive Waste:
 * I can see how this situation might have changed, and why, but this passage does give reason for caution. Hans Adler 22:28, 18 September 2010 (UTC)
 * (ec) Point #1 is correct; the US cannot dump HLW.  Point #3 is a bit misleading, as the reason alternative methods are no longer discussed is the recognition that additional means are not necessary.  In the US, for example, even the lack of a permanent facility like Yucca Mt. hasn't been a real problem.  All the HLW in the US would only cover one single football field to a depth of a few yard.  Some of the early nuclear plants have a full half-century of waste stored on site, and can continue to use such "temporary" means for at least another century.   Furthermore, some of the new GenIV reactor designs on the books generate only a tiny fraction of the waste that current plants do.  Many of those new designs can actually burn the waste of these older plants, turning this "liability" into free energy.   Fell Gleaming <sup style="color:black;">talk  22:46, 18 September 2010 (UTC)
 * I'm only dealing with the London Convention thing, but it seems that there is still confusion here. The London Convention was changed, by the amendment, in 1993 to cover all waste, Hi and Low. All of it. That's what an amendment does; it changes the original convention, law, motion whatever.  Since the US is a party to the convention and accepted the amendment the country is forbidden, like all other countries from dumping waste, high or low. It does not need ratifying, and that's why there is no column for the amendment ratification in the convention status spreadsheet on IMO website. I don't know how many references I need to give you to show that this is the case. that "prohibition of the disposal of radioactive wastes at sea is finally in force for all Contracting Parties to the London Convention" (IMO 2005); "In November 1993, the 16th Consultative Meeting adopted amendments to Annex I prohibiting the disposal of all radioactive wastes at sea". (Principles of international environmental law 2002); Marine issues from a scientific, political and legal perspective 2002 note 49); "The two leaders (of US and Norway) called on Russia to accept the 1993 amendment to the London Convention that establishes a mandatory moratorium on all dumping of radioactive waste at sea"; 1999 Joint US/Norway Press White Statement. That's my last. I've produced multiple high quality sources to support what I've learned, and for whatever reason this continues to be disputed without a single source being produced to back up the contradictory claims.  Perhaps it's moot, though.  It certainly is a highly irrelevant discussion for this page.--Slp1 (talk) 13:34, 19 September 2010 (UTC)
 * I'm only dealing with the London Convention thing, but it seems that there is still confusion here. The London Convention was changed, by the amendment, in 1993 to cover all waste, Hi and Low. All of it. That's what an amendment does; it changes the original convention, law, motion whatever.  Since the US is a party to the convention and accepted the amendment the country is forbidden, like all other countries from dumping waste, high or low. It does not need ratifying, and that's why there is no column for the amendment ratification in the convention status spreadsheet on IMO website. I don't know how many references I need to give you to show that this is the case. that "prohibition of the disposal of radioactive wastes at sea is finally in force for all Contracting Parties to the London Convention" (IMO 2005); "In November 1993, the 16th Consultative Meeting adopted amendments to Annex I prohibiting the disposal of all radioactive wastes at sea". (Principles of international environmental law 2002); Marine issues from a scientific, political and legal perspective 2002 note 49); "The two leaders (of US and Norway) called on Russia to accept the 1993 amendment to the London Convention that establishes a mandatory moratorium on all dumping of radioactive waste at sea"; 1999 Joint US/Norway Press White Statement. That's my last. I've produced multiple high quality sources to support what I've learned, and for whatever reason this continues to be disputed without a single source being produced to back up the contradictory claims.  Perhaps it's moot, though.  It certainly is a highly irrelevant discussion for this page.--Slp1 (talk) 13:34, 19 September 2010 (UTC)

"That's what an amendment does; it changes the original convention, law, motion whatever. Since the US is a party to the convention and accepted the amendment the country is forbidden, like all other countries from dumping waste, high or low. It does not need ratifying"" I'm sorry, but this is demonstrably incorrect.   An amended treaty needs to be ratified to be binding.   Even Wikipedia's own article on treaties verifies this.  Allow me to quote: "There are three ways an existing treaty can be amended. First, formal amendment requires States parties to the treaty to go through the ratification process all over again. The re-negotiation of treaty provisions can be long and protracted, and often some parties to the original treaty will not become parties to the amended treaty. When determining the legal obligations of states, one party to the original treaty and one a party to the amended treaty, the states will only be bound by the terms they both agreed upon. Treaties can also be amended informally by the treaty executive council when the changes are only procedural, technical, or administrative (not principled changes). Finally, a change in customary international law (state behavior) can also amend a treaty, where state behavior evinces a new interpretation of the legal obligations under the treaty."

US Constitutional Law requires congressional approval for all treaty obligations. Congress cannot approve a treaty, then have it amended to different obligations without voting to approve those new obligations.

EDIT: However, in the spirit of compromise, may I suggest the following text, along the lines of "while technically feasible, international law currently forbids most nations from such dumping". That also removes the focus on the US, which at least one editor has complained about. Fell Gleaming <sup style="color:black;">talk 13:50, 19 September 2010 (UTC)
 * As I have stated reliable sources are what is needed here.
 * Find reliable sources to show that this 1993 amendment (in particular) needs to be or has been ratified by the US or any other country for that matter, and I will cave. All the evidence to date, including statements from the IMO that "prohibition of the disposal of radioactive wastes at sea is finally in force for all Contracting Parties to the London Convention",  and those of government and academic sources, show that it is not. This Cambridge University Press} book in note 192 says "That the amendment was adopted with 37 votes in favour, none against, and 7 abstentions, and entered into force in 1994 (not for the Russian Federation, which on 18 February 1994 submitted a declaration of non-acceptance of these amendments)."  It is up to you to provide some proof of the contrary and original research from WP articles is not sufficient.
 * The two reliable sources we have all state that international law forbids nuclear waste dumping (including the one you produced)"it is forbidden by international law." and "violates the treaty that forbids ocean dumping", as well as all the other sources I have presented here.  Please find some reliable sources to support your "compromise" version above "international law currently forbids most nations from such dumping". It is clearly and unambiguously unverifiable original research. --Slp1 (talk) 14:24, 19 September 2010 (UTC)
 * The argument is that it is not binding on the USA as it has not been ratfied by the legilature and thus is not recognised in US law. The US executive may have signed it, but u8ntill the US legilature ratifies it the USA is not bound by it.Slatersteven (talk) 14:47, 19 September 2010 (UTC)
 * That's assuming that this amendment needs to be ratified, as not all amendments do. Nobody has provided a shred of evidence that this one needs to be ratified, and lots has been presented, including the fact that there is no mention of it needing to be ratified on the convention status spreadsheet on IMO website, to show that it doesn't. Find some real concrete evidence to the contrary about this amendment please. --Slp1 (talk) 14:54, 19 September 2010 (UTC)
 * [] It has not been ratified.Slatersteven (talk) 14:56, 19 September 2010 (UTC)
 * You are confusing UNCLOSIII with the London Convention. There is no question that the US hasn't ratified the former, but it has most certainly ratified the later. --Slp1 (talk) 13:10, 20 September 2010 (UTC)


 * Slp, I'm a little surprised by your position, given you yourself have listed several sources that specifically note both the London Convention and Protocol, and UNCLOSIII are not ratified by every nation in the world. Are you actually trying to hide this fact?
 * As for the point about re-ratification being required, if you won't accept Wikipedia or the US Constitution, how about the book Modern Treaty Law and Practice? .  Look to page 266-267.  Or this book documenting the US requirement to re-ratify the amended US Indian treaties: .   Or this British Parliament position paper from last year, showing that the Lisbon Treaty  will need to be re-ratified if amended: .   Or this nearly 100-year old NYTimes article which clearly identifies the constitional issues surrounding ratification of an amended treaty: .   How many more examples do you need?


 * Finally, I think your confusion results from failing to understand one crucial point about the amendment process for international treaties. The usual process (and the process followed by the London Convention) is that an amendment is proposed. If it is acceptable by some supermajority of members (the LC requires a 2/3 majority), then the amendment is passed and comes into force for those members which accepted it.   There are many amended treaties who have multiple binding sets of provisions. Note that, for states which constitutionally require ratification, "acceptance" implies a certificate of ratification, unless the amemdment concerns purely technical implementation details that do not bind parties to new obligations.   Fell Gleaming <sup style="color:black;">talk  15:04, 19 September 2010 (UTC)


 * It's obvious that there is no point continuing with this discussion. You've provided no direct evidence, except general research about treaty ratification requirements, to contradict the mass of reliably sourced evidence that international law prohibits the ocean dumping of radioactive waste. In contrast, I have shown given you links to the specifics of how the London Convention can be amended and who is bound to those amendments. Let me add one more from theJournal of Marine Systems vol 14 1998. pp.377–396: "Amendments to the LC or its annexes must be approved by two-thirds of the contracting parties present at meetings (Curtis, 1993). A state-party which does not vote in favor of an amendment is not bound by its provisions. A state-party which does not participate in a vote on an amendment may ‘opt-out’ of the amendment’s requirements during a 100-day period following its adoption." As we know, US voted in favour or to add low- and intermediate-level radioactive wastes and industrial wastes to Annex I (the black list), did not opt out and is thus bound by the treaty, as has been repeatedly stated by reliable sources about this matter, but for the record, I'll give you a few last references to show that the the LA Timesthee NY TimesAssociated Pressthe EPAand a republican Congressman all consider that the US covered by the ban.
 * I've reverted your edit which is not WP:V verifiable from the sources given, is WP:OR and does not have WP:CONSENSUS. As I said above, not restore it without providing high quality secondary sources that can verify your edits. Slp1 (talk) 14:32, 20 September 2010 (UTC)
 * "the mass of reliably sourced evidence that international law prohibits the ocean dumping" Slp, I truly don't understand why you're having difficulty understanding this. Let's try one more time.  No one disputes your statement there.  "International Law" does prohibit dumping.  The point you can't comprehend is that international law is not the same as national law -- it is binding only upon those nations which have agreed to be bound.     There are very few "international laws" that affect every nation on the planet ... and, as the sources very clearly show, this isn't one of them.   Fell Gleaming <sup style="color:black;">talk  14:51, 20 September 2010 (UTC)
 * Okay, so if I understand you correctly, you would like to point out that the London Convention doesn't apply to countries such as Andorra, Albania, Nepal, Paraguay, Sri Lanka, Vietnam, Thailand, Togo, Trinidad and Tobago, Uruguay etc. This is true, but why is this relevant for this article? Have you got some reliable sources connecting any of these countries to Challenger Deep sub-seabed dumping? --Slp1 (talk) 16:59, 20 September 2010 (UTC)
 * It also doesn't apply to nations like North Korea, Israel, or a few other states that generate nuclear waste. Do you need a source to verify that?  In any case, since you seem emotionally aligned on the issue, I'm willing to agree to a compromise text.  We don't need to identify any nations specifically; just state that dumping is banned per the London Convention and Protocol.   Fair enough?  Fell Gleaming <sup style="color:black;">talk  17:08, 20 September 2010 (UTC)
 * Sorry to have delayed getting back to this. Okay then, do you have any evidence that North Korea, Israel etc  are considering Challenger Deep sub-seabed dumping?  But yes, your suggestion would be fine, since it accurately reflects the sources.   On the other hand your ad hominem insuations about my mental state and motivations are not fine at all. And I notice that the edit you added UNCLOSII] which is not verifiable from the citations given. The only one that mentions is states that UNCLOSII "also has some provisions that can be interpreted" as covering subseabed disposal. Let's go with your suggestion --Slp1 (talk) 00:53, 2 October 2010 (UTC)

What the now-present sources say on feasibility
Re the disputed section (three sentences in total, currently) on nuclear waste disposal, I carefully reviewed the sources currently cited, and revised the text in this edit, for better fidelity to what the sources actually say. FellGleaming evidently agreed that my first two sentences better represented what the sources say, since he left those alone. But he reverted my third-and-final sentence:


 * My 3rd sentence: Scientists differ in their views as to whether such a disposal method might be feasible, with most expressing cautious optimism, but such dumping is forbidden by international law governing dumping of waste.


 * Was Replaced by: The disposal method is technically feasible, but such dumping is forbidden by international law governing dumping of waste.

FellGleaming didn't consider all the sources in current use in the paragraph that apply. There are three, of which only the first is unequivocally favorable to the disposal method. In fact, one of the sources that was cited to support the disposal method actually rejects it in favor of land-based alternatives. Here are the three sources :


 * (1) There's page 187 of Hafemeister, which says this on the subject, "'[Excess weapons grade nuclear materials] could be deposited in very deep ocean trenches, such as the Challenger Deep, located in the Marianas Trench. The Challenger Deep is 11-km deep and slowly subducts into the Earth. This is technically sound but it violates the treaty that bans ocean dumping.'" That's the quote FG relies on exclusively.


 * (2) Then there's this, a single paragraph on [page 279 of An Introduction to Physical Science]. Here's the paragraph in its entirety:"'More down to Earth is the subductive waste disposal method. Subduction refers to a process in which one tectonic plate slides underneath another and is absorbed in the Earth's mantle (see Chapter 21.1). If a repository were located on a subducting plate, both the waste and the plate would be absorbed in the mantle. The most accessible site for the plate repository would be on the ocean floor where plate subduction occurs. The waste would have to be packaged for a long stay on the ocean floor, however, because subduction progresses at only a few centimeters per year. Back to Yucca Mountain.'" It will be obvious to any unbiased editor who examins the paragraph in context that this source implies the disposal method is not feasible, with its "Back to Yucca Mountain", final sentence. Yucca Mountain is, of course, a potential land-based disposal site for radioactive waste.


 * (3) And there's this ref from Berkeley, that says, "'Further studies would be necessary, but several authors think that it is likely that the United States will resort to [subseabed disposal] in the not too distant future. Despite what seems to be cautious optimism by most commentators about the feasibility of [subseabed disposal], it is forbidden by international law.'" Hardly an unequivocal endorsement of feasibility, either.

So which third-sentence for the paragraph better represents the sources we currently have, do you think? I very seldom reinstate something that another editor has deleted, but it's warranted in this case, and I have done so. – OhioStandard  (talk) 22:44, 18 September 2010 (UTC)
 * You are confused. Subseabed disposal is an entirely different group of proposals than subduction plate dumping; the two are in no way synonymous. Nor is a Berkeley Law url an authoritative source for a scientific point.  Just as Viriditas was attempting to use a physics teacher to verify a point of law, you're attempting using a lawyer to verify a technical issue.   Finally, the "Introduction to Physical Science" is a high-school level textbook; the Hafemeister source is more authoritative.  But keep digging, I'm sure you can find someone who disagrees with Hafemeister.   Until you do, however, misrepresenting your sources to claim "scientists disagree" is improper.   And you should know that making contentious changes without consensus when the material is under active talk page discussion is frowned upon.   Fell Gleaming <sup style="color:black;">talk  23:24, 18 September 2010 (UTC)
 * You are the one that is confused, FellGleaming, and if you don't make an attempt to start watching what you say, I'm going to escalate this farther than a simple ANI and noticeboard complaint. There is no indication that The Introduction to Physical Science (2009) book is used solely as a high school level textbook, as the preface and publishers blurb make crystal clear.  The book is considered a college level textbook.  Please read them carefully and show that you have understood what you have read so that I don't have to come back here and correct you again.  The Berkeley Law website, as you have repeatedly been informed, has nothing to do with this topic.  We cannot cherry pick sources to say what we want them to say, based on points we want to personally make.  We use information from the sources, in whole, in full context, and without synthesis. This is very clear.  Please show that you understand it. Viriditas (talk) 02:29, 19 September 2010 (UTC)


 * EDIT. Here is a peer-reviewed paper  on subseabed disposal, so you can see it has essentially nothing in common with the subduction plate dumping approach this article is referring to.  No one is going to build a subseabed repository at Challenger Deep, seven miles beneath the ocean's surface.   Fell Gleaming <sup style="color:black;">talk  23:30, 18 September 2010 (UTC)


 * (e/c) I wasn't attempting to do anything but represent the sources that actually exist in the article at present, as a moment's reflection will make obvious. I didn't put the refs there, and I didn't say I like them: they're just what we have at present. But thanks for pointing out SSD is a different method, I didn't know there was more than one undersea method, and I'm always happy to learn something new. So does anyone (besides FG) think I need to revert the change, i.e. is there really unanimity among scientists that this "subduction plate" method is feasible? Or is it more accurate to say that there's a difference of opinion, with most scientists coming in as "cautiously optimistic" on the question? Or is saying most scientists are "cautiously optimistic" too sanguine? Hmm ... "feasible" usually means, "We think this would work, even though we've never tried it." I'll leave it alone for now, pending the development of the thread above. –  OhioStandard  (talk) 23:33, 18 September 2010 (UTC)


 * I see FellGleaming couldn't wait for other's opinions, and has reverted again. That must mean there's no difference of opinion among scientists as to the feasibility of the subduction method. That's good to know; I suppose scientists must have been doing a trial run for the last thousand years or so, and have found it worked, that no radioactive material escaped? I'm surprised he didn't say "as per talk page consensus" in his edit summary, though. –  OhioStandard  (talk) 23:50, 18 September 2010 (UTC)
 * To see why that HS textbook is a poor source, consider the case of dumping a a typical CANDU fuel rod bundle. At only 10 cm in diameter, dropped horizontally it would subduct in less than three years time.  A more realistic case of a 30x60 cm vitrified block dropped in worst-case alignment would still subduct in about 20 years.  To drive the point further home -- assume it never subducted at all...what then?  Even assuming the radionuclides all eventually wind up dissolved in solution, the amount of becquerels released, when compared to the natural radioactivity found within the ocean itself, is an order of a million times smaller.  Russia has been dumping spent nuclear reactor cores -- without vitrification, packaging, or any other safety mechanisms -- into shallow waters for decades; in some cases only a few hundred feet deep, and extensive studies have found no problems from such . Vitrified material dropped into a 35,000 ft deep trench isn't coming back.
 * As a final point, the reason these measures are no longer widely discussed is simply because they're not necessary. Today's nuclear "waste" is going to be the fuel source of the near future.  Our current reactor designs are 1960s-era technology.  They extract only about 3% of the energy from the fuel.    There are new GenIV designs that burn that "waste", extracting an order of magnitude more energy from it, as well as reducing the volume by as much as a factor of 100.  And of course there's the point that current nuclear reactors have by and large been retaining the waste on site locally for in some cases the last half century.  This "temporary" measure can continue indefinitely without any real problem.  So why fight a public relations campaign to dump it in the ocean?  Fell Gleaming <sup style="color:black;">talk  00:08, 19 September 2010 (UTC)


 * FellGleaming, you need to stop repeating blatant distortions and misinformation. 1)  There is no indication that The Introduction to Physical Science (2009) book is used solely as a high school level textbook, as the preface and publishers blurb make crystal clear.  The book is considered a college level textbook.  I suggest you read the preface.  It's usually a good idea to read a source before you criticize it.  2) There is no indication that it is a "poor source".  3)  The source was chosen for you because you previously failed to identify a single reliable source on this topic.  To date, you still have not found a reliable source on this topic.  Instead of thanking me for helping you, you attacked me for helping you, which is beyond strange.  You are welcome at any time to find another reliable source that supports this topic. Viriditas (talk) 02:25, 19 September 2010 (UTC)
 * Please stop the personal attacks on article talk pages, Viriditas. Furthermore, you're misread my comments.  I did not identify Hafemeister as a high school level textbook, but rather the Introduction to Physical Science source.   Please calm down and avoid the battleground mentality.   Fell Gleaming <sup style="color:black;">talk  02:29, 19 September 2010 (UTC)
 * I've removed the disputed content to the talk page until we have reached consensus on the matter. Stop edit warring and distorting policies and guidelines and work the issues out here on the talk page, taking into consideration what other editors have said and what the noticeboards have said as well. You need to start listening to other editors now, and attempt to reach consensus through reasonable discussion. Viriditas (talk) 02:32, 19 September 2010 (UTC)

You are again violating basic WP policy. I refer you to Don't revert due to "no consensus". Blanking an entire section can be construed as disruptive. Not all that material is under debate. Fell Gleaming <sup style="color:black;">talk 02:40, 19 September 2010 (UTC)
 * You are again misinterpreting Wikipedia policies and guidelines. "Don't revert due to "no consensus" is an essay.  Please learn the difference between essays, policies, and guidelines.  Please also learn the difference between a removal and a revert. When there is no consensus for inclusion, it is best to remove disputed material and discuss on the talk page, taking into consideration the arguments of all editors in favor and against the material.  Please show some good faith that you have understood the problem and you are willing to correct it.  That's how we edit.  Now, you need to start showing a change in behavior.  I want to see you list the problems that have been directed towards your edits here, and I want to see you address those problems with solutions. Viriditas (talk) 02:44, 19 September 2010 (UTC)
 * Viriditas, blanking an entire section because you believe "consensus hasn't been reached" is improper behavior. Hans Adler, Slp, Slatersteven, and myself are slowly reaching consensus on what is an accurate and neutral presentation.  Please join the discussion, rather than blanket reverting mass content.  If you have a specific objection to the current text, please detail it here.  Fell Gleaming <sup style="color:black;">talk  13:16, 19 September 2010 (UTC)
 * FellGleaming, you don't have consensus for your edits, based on the discussion here and on the OR noticeboard. Per WP:BURDEN, you need to develop consensus for your edits here on talk, and you need to use reliable sources about the topic to do it.  I've been trying to help you, since you haven't demonstrated an understanding of how we do research, and I haven't seen the POV you are pushing significantly represented in our sources.  I would therefore ask you to please do some research on this topic first, and to add the reliable sources for the material here on the talk page, instead of repeatedly forcing disputed material into the article.  If this still isn't clear, I would invite you to revisit the OR noticeboard discussion, and directly address the problems raised there.  So far, you've ignored every problem raised on this topic.  We write from the sources, not from our POV. Viriditas (talk) 23:57, 19 September 2010 (UTC)

The above discussion is interesting, but I don't think it belongs here. Are there reliable sources that Challenger Deep in particular, more than other places in deep ocean trenches, is being considered as a disposal site? If not, this should go to a more appropriate article. Jonathunder (talk) 12:43, 3 October 2010 (UTC)


 * It's already mentioned in the nuclear waste and subduction articles, so any more information should go into expanding those sections. I can't imagine anyone choosing the deepest possible trench for disposal, even if other issues were solved, that would just be making life difficult for yourself. Mikenorton (talk) 14:47, 3 October 2010 (UTC)


 * Searching on Google scholar and Google books using the string ' "nuclear waste" disposal "subduction zone" ', gives a few hundred hits, a reasonable proportion of which are relevant, doing the same with the string ' "nuclear waste" disposal "challenger deep" ' gives only a few hits, of which the Hafemeister 2007 book (which only gives the Challenger deep as an example) and one by Williscroft (the only one to mention disposal in the Challenger deep specifically) are the only two to directly link 'nuclear waste disposal' to the 'Challenger deep'. There appears nothing here to suggest that this form of disposal is being seriously considered in the Challenger deep as opposed to subduction zones in general. I would be happy to see this section removed, therefore, as irrelevant to the topic, as shown by a lack of supporting sources. Mikenorton (talk) 09:42, 12 October 2010 (UTC)


 * I agree the section could be removed without harm to the article. In researching this earlier I certainly saw no groundswell of public or scientific-community demand saying, "We must dump nuclear waste in Challenger Deep!" As you say, there have been only a couple of mentions of the trench as a possible example of a subduction zone disposal site. Besides that, the description of subduction zone disposal as feasible is contradicted by multiple sources; from what I found there's certainly no consensus among geophysicists or oceanographers that subduction zone disposal is feasible or risk free.


 * This whole theme was pushed hard by a zealously pro-nuclear editor who (temporarily?) stopped editing on 24 September 2010 and is now subject to community sanctions. I'm under the impression that no one else would mind seeing this section disappear, although it would probably be a good idea to wait awhile longer before deleting it to give others the chance to comment, since so many editors were involved with the section previously. It would probably be a good idea, also, to leave a very clear edit summary indicating that the section is being removed, and following up with a statement to that effect on this talk page, as well, just as a courtesy to future editors who (I really hope they won't) might want to re-open the argument about this at some future date.


 * Oh, also: It would be courteous, should this section be removed, if whoever removes it were to move the relevant text and refs into other relevant articles, e.g. those on nuclear waste and perhaps (?) subduction zones. I know at least two editors put a huge amount of time into researching the matter, coming up with those refs, and making sure the language (well, except for the dubious "technically feasible" comment) was a fair representation of the scientific consensus. –  OhioStandard  (talk) 19:29, 18 October 2010 (UTC)


 * Well I left it for five months and there were no further comments, so I've gone ahead and removed the section. I copied three of the references over to the nuclear waste article as suggested. Mikenorton (talk) 21:45, 23 March 2011 (UTC)


 * Good on you, Mike; I'm glad you remembered this, and I'm grateful for your having followed the process through to its right conclusion. I can't say that I'd actually forgotten about it, but it might just be fair to say I'd not remembered it. ;-) Seriously, though, thanks very much for your diligence. –  OhioStandard  (talk) 05:53, 25 March 2011 (UTC)

"deepest surveyed point"
"The Challenger Deep is the deepest surveyed point in the oceans" leaves one wondering whether there might be other, unsurveyed points that are deeper. It would be good if the article could mention how feasible it is that deeper points might exist, bearing in mind the detail to which the world's oceans have now been mapped. 86.173.36.174 (talk) 18:42, 8 January 2011 (UTC).


 * I think that a change to "deepest known point" would be an improvement, because you're right that the entire globe has now been surveyed, so there aren't many places left that a deeper point could be 'hiding' and they would necessarily be in one of the known deeps, almost certainly in the Marianas trench itself, like the HMRG Deep or in the Tonga Trench, like the Horizon Deep. I'll make the change. Mikenorton (talk) 21:46, 8 January 2011 (UTC)

XPrize Foundation
I reverted an edit that removed this section in the lede. If it is bogus, no doubt there will be other sources that say so. Mikenorton (talk) 19:51, 21 January 2011 (UTC)

obvious error
instead of "table of contents" there is a russian line it says Содержание 79.200.209.129 (talk) 13:34, 9 March 2011 (UTC)
 * Not for me, and there were no edits since you reported this. Maybe someone made a problem in some central configuration file for this site and it was fixed quickly? Hans Adler 14:45, 9 March 2011 (UTC)

Witja deep (11,034 Meters)
The german wikipedia (http://de.wikipedia.org/wiki/Witjastief_1) as well as other german sources (http://content.stuttgarter-zeitung.de/stz/page/2784798_0_9223_-uebers-reisen-n-wie-ngorongoro.html) claim the deepest known point in the oceans is the "Witja Deep 1", which is 11,034 meters deep. It is part of the Mariana Trench as well and has been discovered by a russian exploration ship in the year 1957. Unless anyone can provide sources that claim otherwise, I propose to change the sentence "The Challenger Deep is the deepest known point in the oceans" to "The Challenger Deep is the second deepest known point in the oceans". 87.123.58.44 (talk) 12:12, 30 November 2011 (UTC)
 * If that were true, it would be surprising if you couldn't find a reliable English source. I would have expected someone to have written about it in the intervening 53 years.  I doubt whether your one German source trumps all the sources for Challenger Deep. - David Biddulph (talk) 13:08, 30 November 2011 (UTC)
 * The Expedition of the vessel Witjas (engl. Vityaz) was part of the 1957 International Geophysical Year. The report is a scientific, official source, not a news paper, and base for all continental European atlas publication. I do not know any serious map collection outside of biased US sources that names the Challenger deep as the deepest known spot. It is always Witjas-1 (Vityaz-1). --2605:6001:E245:D100:91D:C85E:393D:6116 (talk) 03:24, 3 February 2018 (UTC)
 * This observation has never been replicated - it is already discussed in the article. Mikenorton (talk) 10:45, 3 February 2018 (UTC)


 * This spot is referred to as the "Mariana Hollow" in the article on the 1957 Russian soundings. Since later and better sounders have not confirmed it, it remains dubious. Since these things don't measure depth to any better than +/- 20 m anyway, we may as well go with the latest and best figures, as the greater depth of the 1957 measurement is well within margin of error, especially with the old equipment. S  B Harris 18:07, 30 November 2011 (UTC)

2011 updated data
Can somebody please integrate the following new information (sorry, don't have time to do it myself right new): http://www.bbc.co.uk/news/science-environment-15845550 Guinness2702 (talk) 14:34, 7 December 2011 (UTC)


 * Done.  Pyrop e  16:35, 7 December 2011 (UTC)

Nereus "record"
"Nereus thus became the first vehicle to reach the Mariana Trench since 1998". Is being first after last time someone/something else did somewhat notable? --ElfQrin (talk) 18:14, 18 March 2012 (UTC)

James Cameron Just made it
Sorry, don't have time to update at the moment. http://www.bbc.co.uk/news/science-environment-17503395 — Preceding unsigned comment added by 94.30.98.63 (talk) 23:14, 25 March 2012 (UTC)


 * I can't believe he didn't learn from experience of two Trieste dives, including the deepest, that "whited out" all visibility, once from hitting the bottom, thus ending all chance of seeing anything on that dive. The two challenges to getting to the bottom of Challenger deep are 1) making it there and back alive, and 2) seeing anything when you're there! A successful run is going to need a craft that touches down on spidery legs like the Lunar Module or one of those bacteriophages that have legs. S  B Harris 00:23, 26 March 2012 (UTC)

"On March 25, 2012, Hollywood director James Cameron claimed a solo manned descent to the bottom of Challenger Deep, only the second since that done by Trieste in 1960." I think he is the --only-- solo diver. The Trieste was manned by a duo. — Preceding unsigned comment added by 66.55.214.116 (talk) 00:57, 26 March 2012 (UTC)
 * Fixed with a qualifier. Second manned dive, first solo. S  B Harris 01:01, 26 March 2012 (UTC)

The starting and bottom reaching times are given as 18:15 UTC Sunday (05:15 Monday, local time) and 21:52 UTC Sunday (07:52 Monday, local time), and is said The descent lasted 2 hours and 36 minutes. Well, 7:52 - 5:15 equals 2:37, that's ok. But 21:52 - 18:15 equals 3:37, so I think there is an error (or something to be explained). 82.141.124.77 (talk) 09:09, 27 March 2012 (UTC)

Horizon Deep
Interesting that Horizon Deep doesn't have an article, though HMRG Deep and Challenger Deep do... perhaps some mention of comparative deeps should occur here? HMRG Deep has some comparative information. 70.24.244.198 (talk) 09:37, 27 March 2012 (UTC)

pressure math
"1,099 times that at the surface, or 111 MPa". 111 MPa is exactly equal to 1,110 bars (1,110 times that at the surface). Does anyone have access to the source (Marine Micropaleontology, Volume 42, Issues 1–2, May 2001, Pages 95-97) to clarify which way it reported the pressure, so we can change one of these numbers to agree with the other? -- JHunterJ (talk) 11:38, 12 April 2012 (UTC)


 * From the seawater article; The density of surface seawater ranges from about 1,020 to 1,029 kg•m−3, depending on the temperature and salinity. Deep in the ocean, under high pressure, seawater can reach a density of 1,050 kg•m−3 or higher.
 * If that article is right the water column pressure at great depth might be more complex than it seems due to salinity, temperature and compression interaction effects.--Francis Flinch (talk) 17:11, 12 April 2012 (UTC)


 * Just looking at unit conversion, mean surface pressure is 101.3 kPa = 1.013 bars by convention. Thus, 111 MPa is 111/1.013 = 1095.7 times surface pressure, or 1096 times to 4 sig digits, not 1099 times. It's 1110 bars or 1110 atm only at 3 sig digits. If (on the other hand) you take the number 1099 times surface P as the primary data, and multiply by 1.013, you get 1113 times surface to 4 digits, not 1110. So again, something is wrong here at the 4th digit in just the conversion. But I don't know the primary number. Physically, for reasons explained by the poster above, this pressure number would need to be measured directly to the 4th digit, as calculation by guessing at the mean density of the water in the column would only give you something accurate to 2 sig digits. In order to do better than 2 digits by semi-empirical calculation, this would have to be numerically integrated as P(total) = P(surface) + g ∫ ρ(x)dx where ρ(x) is water density as a function of depth and x is depth, with integration limits of zero to the max depth of Challenger Deep. Of course you must know density(x) as a function of depth x. This can't be measured directly by instruments, which only measure total pressure!, so you'd have to indirectly model this with seawater density ( as a function of pressure numbers ρ(P) that come out of a lab, and do the whole thing as a numerically solved differential equation dP/dx = g ρ(P(x)), like calculating pressures at depth in the Sun. Since, as noted, water density varies with depth/pressure at the 3rd sig digit (it's not perfectly incompressable-- nothing is). In any case, if somebody measured the pressure directly at 111 MPa (3 digit accuracy), we should be reporting the figure of "times standard atm" only to 3 digits, not the 4 digits of 1099 atm. Thus, 1.11 x 10^4 times standard atmospheres, in order to make the uncertainty more explicit. If somebody measured 1099 atm, on the other hand, we can and should give MPa pressure to 4 digits, which is 111.3 MPa. S  B Harris 19:01, 12 April 2012 (UTC)


 * I stand corrected, then, if 1 bar isn't surface pressure. But 1096 at 4 sig figs is 1100 (not 1110) at 3 sig figs -- unless I'm making another bad assumption somewhere. Thanks for the rest of that analysis -- fully agreed. -- JHunterJ (talk) 21:29, 12 April 2012 (UTC)
 * Sure enough. 1096 (4 digits) = 1100 (3 digits), or of course, better written 1.10 x 103. And you have to take into account surface pressure of about 1 atm (as an old scuba diver I should have remembered that!) Thanks. Doing the simple mean pressure as P = 101300 N/m^2 + ρgh, where ρ is put at 1040 kg•m−3 (the mean of the numbers you give for density) and depth is taken as 10900 m, we get a pressure of 1.113 x 10^8 N/m^2 or 111.3 MPa or 1113 bar. Not bad, for a rough back-of-envelope guess! Anyway, we have to find the original pressure measurement by one or more manned or unmanned submersibles. S  B Harris 16:44, 13 April 2012 (UTC)
 * In the atmosphere (unit) article various ways to express pressure are dealt with. The MPa and bar can be interchanged without much thought and definition effort. Surface pressure sadly is not constant. The density of air article explains this. The Standard conditions for temperature and pressure, International Standard Atmosphere and U.S. Standard Atmosphere articles are also worth reading. Beware the International Standard Atmosphere defines the average air pressure at mid latitudes at sea level for dry air (0% relative humidity) at 15°C. This 0% relative humidity atmospheric condition will be virtually impossible over the seawater covered Challenger Deep. Humidity has a counter intuitive impact. Since water vapor has a density of 0.8 grams per litre, while dry air averages about 1.225 grams per litre, higher humidity actually decreases the air density. Like other locations the air density (and the weather) over the Challenger Deep will vary.
 * For this article the main concern is the water column pressure at great depth that might be more complex than it seems due to salinity, temperature and compression interaction effects. The Pascal and psi are the preferred SI and Imperial units to express pressure.--Francis Flinch (talk) 08:53, 13 April 2012 (UTC)


 * To be sure, but I'm not sure the reader really cares that the pressure at depth in the Challenger Deep is some multiple of the LITERAL barometric air-pressure that day above the surface of the ocean in the southwest Pacific, off Guam. I think multiples of a standard atmosphere (1.013 bar), just as a way to get the mind around it, would do fine. S  B Harris 16:44, 13 April 2012 (UTC)

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 * Added archive https://web.archive.org/web/20120329032435/http://tritonsubs.com/submersibles/triton-360003/ to http://tritonsubs.com/submersibles/triton-360003/
 * Added archive https://web.archive.org/web/20081203173230/http://www.americanheritage.com/articles/magazine/it/1992/1/1992_1_28.shtml to http://www.americanheritage.com/articles/magazine/it/1992/1/1992_1_28.shtml
 * Added archive https://web.archive.org/web/20090403201531/http://www.marianatrench.com/default.htm to http://www.marianatrench.com/default.htm

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 12:57, 21 January 2018 (UTC)

Pressures?
This article makes no mention of water pressure and temperature as this depth, or any other environmental information that the reader might find interesting. The numerous reports on the inconsistent sounding readings could certainly be condensed into one section or subsection. — Preceding unsigned comment added by 74.65.17.245 (talk) 14:44, 17 March 2018 (UTC)

New World Record
Please see https://www.bbc.com/news/science-environment-48230157 and other links to be added as they come on line. New world record dives recorded in Challenger Deep as part of FiveDeeps.com expedition. --Brad Patrick (talk) 14:56, 13 May 2019 (UTC) Another discussion about the measurement. See https://www.wired.com/story/deepest-solo-dive-ever/. Five Deeps believes they succeeded in diving to 10,924m +/- 4 meters (one standard deviation), which is 10,928m, the same as the Japanese estimated in 1984.--Brad Patrick (talk) 14:45, 23 September 2019 (UTC)

Physical Description of Length and Width of Challenger Deep
This article states in first para "The Challenger Deep is a relatively small slot-shaped depression in the bottom of a considerably larger crescent-shaped oceanic trench, which itself is an unusually deep feature in the ocean floor. The Challenger Deep's bottom is about 11 km (7 mi) long and 1.6 km (1 mi) wide, with gently sloping sides.[1]" This seems to be incorrect The entire Challenger Deep can be seen in Fig. 2, stretching from about 142-08' East to about 142-37' East at about 11-22' north latitude. Twenty-nine minutes of longitude at 11.35-degs north, equates to about 28.8 nautical miles (59.73/60*29) in length. Thus the Challenger Deep is about 29 nautical miles in length (NOT seven statue miles as stated in the first para). The width of about 1 nautical mile is approximately correct - depending on what depth gradient is selected to define the width. In 1995, 1998, 1999 and 2002, the Kaiko expeditions surveyed the Challenger Deep, and includes the statement: "Challenger Deep consists of three en echelon depressions along the trench axis, each of which is 6–10 km long, about 2 km wide, and deeper than 10,850 m. The eastern depression is the deepest, with a depth of 10,920 ± 5 m." The following .gif shows all three depressions: west, center, and east. THIS GIF shows the east depression as about one nautical mile in width, and about four nautical miles (8 km) in length at the 10,850 meter depth line. Thus I suspect that the 11 km x 1.6 km "deep" in the existing article is describing the east depression of the Challenger Deep ONLY, at some depth line a bit less deep than that shown in the GIF above. Several documents show that the 1960 manned dive by Piccard and Walsh in the bathyscaphe Trieste was to a location at about longitude of 142-15'East -- that is into the west depression. Online documents show that both James Cameron's 2012 dive, and Victor Vescovo's three dives in 2019 (two were solo dives by Vescovo; and one dive was made by Patrick Lahey and Jonathan Struwe) at or close to 142-35' East, which was called the "Eastern Pool" by Vescovo. Vescovo's expedition also targeted the center depression with a manned dive in May 2019, with Patrick Lahey and John Ramsay, diving near 142-20 East. The best graphic I have seen, showing the three-depression character of the Challenger Deep, is found at It is located in the Pacific Ocean, at the southern end of the Mariana Trench south of the Mariana Islands group. The Challenger Deep is a relatively small slot-shaped depression at the bottom of a considerably larger crescent-shaped oceanic trench, which itself is an unusually deep feature in the ocean floor. The Challenger Deep consists of three basins, each over 10,850 m in depth, oriented in echelon from west to east, separated by mounds between basins two to three hundred meters higher. It extends about 48 kilometers (30 mi) west to east if measured at the 10,850 m isobath:https://www.merriam-webster.com/dictionary/isobath. Both the western and eastern basins have recorded depths (by sonar bathymetry) in excess of 10920 m, while the center basin is slightly shallower. The closest land to the Challenger Deep is Fais Island (55 mi west of Ulithi atoll). The Challenger Deep is 287 km (178 mi) northeast of Fais Island, and 304 km (189 mi) southwest of Guam. It is located in the ocean territory of the Federated States of Micronesia.[2]

HELP NEEDED. HELP HELP HELP -- I don't know how to establish a illustration. The following illustration should become a part of the article: https://commons.wikimedia.org/wiki/File:Challenger_Deep_EM124_Sonar_Map_and_Diving_History_101119.jpg

Note that the last sentence is herein modified by eliminating the statement about 1.6 kilometers outside of Guam's ocean area. Since the Challenger Deep is almost 30 miles long, talking about 1.6 kilometers begs the question, "exactly what is being measured". Deletion is the best solution.Gwyncann (talk) 22:19, 13 October 2019 (UTC)


 * Can the It extends about 48 km (30 mi) west to east if measured at the 10,850 m (35,597 ft) isobath. sentence be better sourced? It seems logical that the deepest spots should be over 11,000 m deep for the seabed to rise 200 to 300 m between the basins for such a feature.--Francis Flinch (talk) 18:45, 15 October 2019 (UTC)

As the mounds are measured from the surface, they are at less depth. Thus the mounds are at depths 10,850 m minus 200 to 300 meters, i.e. 10,550 m to 10,650 m. or even less. Recommend remodifying depths to the 10,850 isobath, as that is the depth by which both the Kaiko expedition and the Vescovo expedition provided sonar bathymetric charts. There has only been one report of depths exceeding 11,000 meters -- the Russian R/V Viytaz in 1957. This reported hole was about 1.25 nms north of the center of the western basin -- demonstrating that navigation and depth accuracy in 1957 do not compare to those developed since the availability of GPS and multi-beam sonar bathymetry. 02:06, 17 October 2019 (UTC)Gwyncann (talk)

I propose adding the following sections and deleting the sentences and paragraphs that presently provide much less info and relatively poor references. The below is referenced back to original data, books, scientific papers, etc. Gwyncann (talk) 07:12, 27 October 2019 (UTC)

Surveys and Bathymetry
1875 – HMS Challenger – In 1875, during her transit from the Admiralty Islands to Yokohama, the three-masted sailing corvette HMS Challenger attempted to make landfall at Guam, but was set to the west by “baffling winds” preventing them from “visiting either the Carolines or the Ladrones.” These winds pushed her track to the west, across the 35-mile-long depression which, 85-years later, would achieve prominence as the Challenger Deep. Even more amazing, one of her thirteen sampling stations on that 2,300 nm track to Japan was within fifteen miles of the deepest depression in the world’s oceans.'' On 23 March 1875, at sample station number #225, HMS Challenger recorded the bottom at 4,475 fathoms (8,184 m / 26,850 ft) deep, (the deepest sounding of her three-plus-year eastward circumnavigation of the Earth) at 11°24’ N / 143°16’ E -- and confirmed it with a second sounding at the same location. Depth soundings were by Baillie-weighted marked rope, and geographical locations were determined by celestial navigation (to an estimated accuracy of two nautical miles). The serendipitous discovery of Earth’s deepest depression by history’s first major scientific expedition devoted entirely to the emerging science of oceanography, was incredibly good fortune, and especially notable when compared to the Earth’s third deepest site (the Sirena Deep only 150 nautical miles east of the Challenger Deep), which would remain undiscovered for another 122 years.

1951 – S/V HMS Challenger II – Seventy-five years later, the 1140-ton British survey vessel HMS Challenger II, on her three-year westward circumnavigation of Earth, investigated the extreme depths southwest of Guam reported in 1875 by her predecessor, HMS Challenger. On her southbound track from Japan to New Zealand (May-July 1951), the Challenger II conducted a survey of “the Marianas Trench (sic) between Guam and Ulithi” (using seismic-sized bomb-soundings) and recorded a maximum depth of 5,663 fathoms (10,356 m /33,978 ft). The depth was beyond the Challenger II’s echo sounder capability to verify, so they resorted to using a taut wire with “140-lbs of scrap iron”, and documented a depth of 5,899 fathoms (10,788 m /35,394 ft). In New Zealand, the Challenger II team gained the assistance of the Royal New Zealand Dockyard, “who managed to boost the echo sounder to record at the greatest depths.” They returned to the “Marianas Deep” (sic) in October, 1951. Using their newly improved echo sounder, they ran survey lines at right angles to the axis of the trench and discovered “a considerable area of a depth greater than 5,900 fathoms” -- later identified as the Challenger Deep’s western basin. The greatest depth recorded was 5,940 fathoms (10,863 ± 35 m /35,640 ft), at 11°19′N, 142°11.5′E. Navigational accuracy of “several hundred meters” was attained by celestial navigation and LORAN-A. 1957-1958 – R/V Vityaz – In August 1957, the 3248-ton Soviet research vessel Vityaz recorded a maximum depth of 11,034 ± 50 m / 36,201 ft depth at the western basin of the Challenger Deep at 11°20.9′ N, 142°11.5′ E. Fisher records a total of three Vityaz sounding locations on Fig.2 "Trenches" (1963), one within yards of the 142°11.5' E location, and a third at 11°20.0’ N, 142°07' E, all with 11,024 m depth. Both the depth and the geographical location are statistical outliers, and have not been duplicated or verified by later visits to the Challenger Deep. Navigation was by celestial navigation. If Vityaz had access to LORAN equipment, it is difficult to explain an apparent navigational error in excess of three nautical miles when compared to modern geographical localization of the western basin’s deepest depth. The depth recorded originally as 11,034 ± 50 m exceeds modern measurements of the western basin by over 100 meters. Taira reports that if the Vityaz’s depth was corrected with the same methodology used by the Japanese r/v Hakuho Maru expedition of December 1992, it would be presented as 10,983 ± 50 m, as opposed to modern depths reported as 10,907 ± 13 m in the western basin. The error bars still do not overlap. The Vityaz depth remains an outlier.

1959 – R/V Stranger – The first definitive verification of both depth and location of the Challenger Deep (western basin) was determined by Dr. R. L. Fisher from the Scripps Institution of Oceanography, aboard the 325-ton research vessel Stranger. Using explosive soundings, they recorded 10,850 ± 20 m in July 1959. The Stranger used celestial and LORAN-C for navigation. LORAN-C navigation provided geographical accuracy of 460 meters or better. Discrepancies between the geographical location (lat/long) of the Stranger’s deepest depths and those from earlier expeditions Challenger II 1951; Vityaz 1957 & 1958) “are probably due to uncertainties in fixing the ships’ positions.” 	The Stranger’s north-south zig-zag survey passed to the east of the eastern basin southbound, and to the west of the eastern basin northbound, thus failed to discover the eastern basin of the Challenger Deep. The maximum depth measured near longitude 142°30’E was 10,760 ±20 m, about 10 kms west of the eastern basin’s deepest point. This was an important gap in information, as the eastern basin was later reported as deeper than the other two basins.	The Stranger crossed the center basin twice, measuring a maximum depth of 10,830 ±20 m in the vicinity of 142°22’E. At the western end of the central basin (approximately 142°18’E), they recorded a depth of 10,805 ±20 m. The western basin received four transects by the Stranger, recording depths of 10,830 ±20 m toward the central basin, near where the Trieste dove in 1960 (vicinity 11°18.5’N / 142°15.5’E), and where the Challenger II, in 1950, recorded 10,863 ±35 m. At the far western end of the western basin (about 142°11’E), the Stranger recorded 10,850 ±20 m, some 6 kms south of the location where the Vityaz recorded 11,034 m in 1957-1958. Fisher stated: “…differences in the Vitiaz (sic) and Stranger-Challenger II depths can be attributed to the [sound] velocity correction function used…” After investigating the Challenger Deep, the R/V Stranger proceeded to the Philippine Trench and transected the trench over twenty times in August 1959, finding a maximum depth of 10,030 ±10 m, and thus establishing that the Challenger Deep was 800 meters deeper than the Philippine Trench. The 1959 Stranger surveys of the Challenger Deep and of the Philippine Trench informed the U.S. Navy as to the appropriate site for the bathyscaph Trieste,’s record dive in 1960.

1960 – Bathyscaph Trieste – On 23 January 1960, the U.S. Navy bathyscaph Trieste, piloted by Swiss engineer Jacques Piccard and Navy Lieutenant Don Walsh, dove at/near 11°18.5’N / 142°15.5’E, bottoming at 10,910 ±10 m (35,800 ft) in the western basin, as measured by an onboard manometer. Navigation of the support ships was by celestial and LORAN-C with an accuracy of 460 meters or less. I will wait a week for comments, suggestions, corrections before editing the main article by adding the above. All help and comments would be welcome.Gwyncann (talk) 07:12, 27 October 2019 (UTC) Now working on the R/V Thomas Washington's surveys of the Challenger Deep - several from 1975 to 1980. I will be cleaning them up on this page to add links and references appropriately. Here goes:Gwyncann (talk) 07:50, 9 November 2019 (UTC) 1975 – R/V Thomas Washington – The Scripps Institution of Oceanography deployed the 1,490-ton Navy-owned, civilian-crewed research vessel Thomas Washington (AGOR-10) to the Mariana Trench on several expeditions from 1975 to 1986. The first of these was the Eurydice Expedition, Leg 8 which brought Dr. Robert L. Fisher back to the Challenger Deep’s western basin 28-31 March 1975. The Thomas Washington navigated by (SATNAV) with Autolog Gyro and EM Log. Bathymetrics were by a 12 Khz Precision Depth Recorder (PDR) with a single 60° beam. They mapped one, “possibly two,” axial basins with a depth of 10915 m ±20 m.  Five dredges were hauled 27-31 March, all into or slightly north of the deepest depths of the western basin. Fisher noted that this survey of the Challenger Deep (western basin) had "...provided nothing to support and much to refute recent claims of depths there greater than 10915 m ±20 m." While Fisher missed the eastern basin of the Challenger Deep (for the third time), he did report a deep depression about 150 nautical miles east of the western basin. The 25 March dredge haul at 12.062°N, 142.557°W encountered 10015 m, which pre-shadowed by 22 years the discovery of the HMRG Deep/Sirena Deep]] in 1997. The deepest waters of the Serina Deep at 10714 m ±20 m are centered at/near 12.06567°N, 142.5811°W, approximately 2.65 kms from Fisher's 25 March 1975 10015 m dredge haul.--Gwyncann (talk) 08:18, 9 November 2019 (UTC) 1976, 1977 – R/V Thomas Washington – On Scripps Institution of Oceanography's INDOPAC Expedition Leg 3, the chief scientist, Dr. Joseph L. Reid, and oceanographer Arnold W. Mantyla made a hydrocast of a free vehicle (a special-purpose benthic lander for measurements of water temperature and salinity) on May 27, 1976 into the western basin of the Challenger Deep, "Station 21," at 11°19.9'N, 142°10.8'E at about 10,820 meters depth. On INDOPAC Expedition Leg 9, under chief scientist Dr. A. Aristides Yayanos, the Thomas Washington spent nine days from 13-21 January 1977 conducting an extensive and detailed investigation of the Challenger Deep, mainly with biological objectives. “Echo soundings were carried out primarily with a 3.5 kHz single-beam system, with a 12 kHz echosounder operated in addition some of the time,” (the 12 kHz system was activated for testing on January 16). A baited “free camera” (sic – a lander) was put into the western basin (11°19.7’ N, 142°09.3’ E), on 13 January, bottoming at 10,663 m and recovered 50 hours later in damaged condition. Quickly repaired, it was again put down on the 15th to 10,559 meters depth at 11°23.3’ N, 142°13.8’ E. It was recovered on the 17th  with excellent photography of amphipods (shrimp) from the Challenger Deep’s western basin. The baited camera was put down for the third and last time on the 17th, at 11°20.1N, 142°25.2 E, in the central basin at a depth of 10,285 meters. The baited camera was lost and may remain on the bottom in the vicinity of 11°20.1N, 142°25.2 E. Free traps and pressure-retaining traps were put down at eight location from 13 to 19 January into the western basin, at depths ranging from 7,353 to 10,715 meters. Both the free traps and the pressure-retaining traps brought up good sample amphipods for study. While the ship briefly visited the area of the eastern basin, the expedition did not recognize it as potentially the deepest of the three Challenger Deep basins. --Gwyncann (talk) 08:18, 9 November 2019 (UTC)--Gwyncann (talk) 05:13, 11 November 2019 (UTC) The Thomas Washington returned briefly to the Challenger Deep on 17-19 October 1978 during Mariana Expedition Leg 5 under chief scientist James W. Hawkins. The ship tracked to the south and west of the eastern basin, and recorded depths between 5,093 to 7,182 meters. Another miss. On Mariana Expedition Leg 8, under chief scientist Dr. A. Aristides Yayanos, the Thomas Washington was again involved, from 12-21 December 1978, with an intensive biological study of the western and central basins of the Challenger Deep. Fourteen traps and pressure-retaining traps were put down to depths ranging from 10,455 to 10,927(!) meters, the greatest depth was at 11°20.0 N, 142°11.8 E. All of the 10,900-plus meter recordings were in the western basin. The 10,455 depth was furthest east at 142°26.4’ E (in the central basin), about 17 kms west of the eastern basin. Again, focused efforts on the known areas of extreme depths (the western and central basins) was so tight that the eastern basin again was missed by this expedition. --Gwyncann (talk) 08:18, 9 November 2019 (UTC)

From 20 to 30 November 1980, the Scripps research vessel Thomas Washington was onsite at the western basin of the Challenger Deep, as part of Rama Expedition Leg 7, again with chief-scientist Dr. A.A. Yayanos. Yayanos directed the Washington into arguably the most extensive and wide-ranging of all single-beam bathymetric examinations of the Challenger Deep ever undertaken, with dozens of transits of the western basin, and also ranging far into the backarc of the Challenger Deep (northward) and significant excursions into the forearc (southward), and along the trench to the east. They hauled eight dredges in the western basin to depths ranging from 10,015 to 10,900 meters; and between hauls, cast thirteen free vertical traps. The dredging and traps were for biological investigation of the bottom, but provided bathymetrics at each bottom event. Once again, other than a brief look into the eastern basin, all bathymetric and biological investigations were into the western basin. --Gwyncann (talk) 23:32, 9 November 2019 (UTC)

1986 – R/V Thomas Washington – The mounting of one of the first commercial multi-beam echosounders capable of reaching into the deepest trenches, i.e. the 16-beam Seabeam “Classic,” on the Thomas Washington’s 1986 Papatua Expedition, Leg 8. This allowed the chief-scientist, Dr. A.A. Yayanos, an opportunity to transit the Challenger Deep with the most modern depth-sounding equipment. During the pre-midnight hours of 21 April 1986, the multibeam echosounder produced a map of the bottom with a swath of about 5-7 miles wide. The maximum depth recorded was 10,804 meters. Yayanos noted: “The lasting impression from this cruise comes from the thoughts of the revolutionary things that Seabeam data can do for deep biology.” --Gwyncann (talk) 23:32, 9 November 2019 (UTC)


 * Thanks for your additions. The abbrevation kms for kilometers looks quite odd for a metric units accustomed reader like me. I am accustomed to read a number over 1 km when several kilometers are meant. In en Wikipedia it is nice to use auto conversions like 13 km or 10 nmi for readers that are not accustomed to the used units. I would treat the multiple RV Thomas Washington cruises alike the 1998, 1999 and 2002 – RV Kairei cruises. You can consider using several paragraphs since your information is quite detailed. If you can find and source conflicting data regarding depths and positions etc. it is a good idea to mention that. Wikipedia prefers external reference sources that can be read online over other sources. Using non-internet available references like books is of course ok.--Francis Flinch (talk) 13:28, 9 November 2019 (UTC)

Thanks Francis. I'll reformat the Washington surveys as one very long entry -- like the Kairei if you want. But when I get to the Kairei surveys, it might become as cumbersome as these five visits by the Washington. I had in mind to present each chronologically, as the US surveys interleave with the Japanese surveys, and each built on the data discovered by all predecessors. If I had my druthers, I would prefer to eventually present a completely chronological order of surveys. My research has uncovered about 28 surveys to the Challenger Deep, from the 1875 HMS Challenger to the Five Deeps Pressure Drop in 2019, and I'm putting them all together as I finish each investigation. --Gwyncann (talk) 23:32, 9 November 2019 (UTC)

Next batch coming up -- mostly from 1992 - 1998. Still not ready for the Kairei surveys.05:14, 12 November 2019 (UTC)Gwyncann (talk)

1962 – R/V Spenser F. Baird – The Proa Expedition, Leg 2, returned Dr. R. L. Fisher to the Challenger Deep on 12-13 April 1962 aboard the Scripps research vessel Spencer F. Baird (formerly the steel-hulled US Army large tug LT-581) and employed a Precision Depth Recorder (PDR) to verify the extreme depths previously reported. They recorded a maximum depth of 10915 m (location not available). Additionally, at location “H-4” in the Challenger Deep, the expedition cast three taut-wire soundings: on April 12, the first cast was to 5078 fathoms (corrected for wire angle) 9287 m at 11.38333°N, 142.325°W in the central basin. (Up until 1965, US research vessels recorded soundings in fathoms.) The second cast, also on 12 April, was to 5000+ fathoms at 11.34167°N, 142.375°Win the central basin. On April 13, the final cast recorded 5297 fathoms (corrected for wire angle) 9687 m at 11.29167°N, 142.18333°W (the western basin). They were chased off by a hurricane after only two days on-site. Once again, Fisher entirely missed the eastern basin of the Challenger Deep, which later proved to contain the deepest depths.

1988 – R/V Moana Wave – On August 22, 1988, the U.S. Navy-owned 1000-ton research vessel Moana Wave (AGOR-22), operated by the Hawaii Institute of Geophysics (HIG), University of Hawaii, under the direction of chief scientist Robert C. Thunell from the University of South Carolina, transited northwesterly across the central basin of the Challenger Deep, conducting a single-beam bathymetry track by Precision Depth Recorder. The deepest echosoundings recorded were 10656 m to 10916 m, with the greatest depth at 11.36667°N, 142.41667°W. This was the first indication that all three basins contained depths in excess of 10900 m.

1988 – R/V Moana Wave – On August 22, 1988, the U.S. Navy-owned 1000-ton research vessel Moana Wave (AGOR-22), operated by the Hawaii Institute of Geophysics (HIG), University of Hawaii, under the direction of chief scientist Robert C. Thunell from the University of South Carolina, transited northwesterly across the central basin of the Challenger Deep, conducting a single-beam bathymetry track by their 3.5 khz narrow (30-degs) beam echosounder with a Precision Depth Recorder. In addition to sonar bathymetry, they took 44 gravity cores and 21 box cores of bottom sediments. The deepest echosoundings recorded were 10656 m to 10916 m, with the greatest depth at 11.36667°N, 142.41667°W in the central basin. This was the first indication that all three basins contained depths in excess of 10900 m.Gwyncann (talk) 07:23, 25 November 2019 (UTC)

Adding a bit more infor to 1988 Moana Wave: this was an acoustic and bottom sediment survey only -- no gravity/magnetic/seismic studies. They had a 3.5 khz narror beam echosounder (30-deg beam) had GPS and SatNav, and took 44 gravity cores and 21 box cores. Gwyncann (talk) 07:23, 25 November 2019 (UTC)

1996 – S/V Yokosuka – For most of 1995 and into 1996, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) employed the 4439-ton ROV support vessel Yokosuka to conduct the testing and workup of the 11000 meter remotely-operated vehicle (ROV) Kaiko, and the 6500 meter ROV Shinkai. It was not until February, 1996, during the Yokosuka’s cruise Y96-06, that the Kaiko was ready for its first full depth dives. On this cruise, JAMSTEC established an area of the Challenger Deep (11°10’N to 11°30’ N, by 141°50’ E to 143°00’ E -- which later were recognized as containing three separate pool/basins en echelon, each with depths in excess of 10,900 meters) toward which JAMSTEC expeditions would concentrate their investigations for the next two decades. The culmination of the workup of the ROV Kaiko brought the Yokosuka to the central basin, where the ROV made three dives, Kaiko #21 – Kaiko #23, from February 29 to March 4, 1996. Depths ranged from 10898 m at 11.3756°N, 142.4403°W, to 10896 m at 11.3765°N, 142.4308°W; dives #22 & #23 to the north, and dive #21 northeast of the deepest waters of the central basin. The deepest measurement was 10911.4 m. The ROV Kaiko was the first vehicle to visit to the bottom of the Challenger Deep since the bathyscaphTrieste’s dive in 1960, and the first success in sampling the trench bottom mud, from whichKaiko obtained over 360 samples. Approximately 3000 different microbes were identified in the samples. The Yokosuka employed a 151-beam SeaBeam 2112 12-khz multibeam echosounder, allowing search swaths 12-15 km in width at 11000 m depth. The depth accuracy of the Yokosuka’s Seabeam was about 0.1% of water depth (i.e. ± 100 m for 10000 m depth). The ship’s dual GPS systems attained geodetic positioning within double digit meter (100 m or better) accuracy.Gwyncann (talk) 23:27, 17 November 2019 (UTC)

I'm going up with the above for the first Yokosuka survey of the Challenger Deep. Its not well documented on Darwin, but several later surveys report on it, and its place in the history of the Kaiko is significant.Gwyncann (talk) 23:27, 17 November 2019 (UTC)

1997 -- R/V Melville w/Hawai'i MR1 – Hawaii MR1 is short for HIGP (Hawaiʻi Institute of Geophysics and Planetology) Acoustic Wide Angle Imaging Instrument, Mapping Researcher 1. [2] This system is the first to use all-digital signal processing. [2] It has been used in the discovery of several objects and locations of note, examples being the USS Yorktown [3] and the HMRG Deep. [4]

Something happened and the new section on Kairei 1998-99 was not properly uploaded. Here is the second try: I'll be wikifying the below this weekend and upload as soon as I can finish. I'm splitting off the Kairei 2002 survey because they came to a very different opinion than did the 1998-99 surveys. Thanks to Francis and others who are beefing up the wikification of the earlier uploaded surveys.Gwyncann (talk) 07:42, 22 November 2019 (UTC): 1998, 1999 – RV Kairei –  Cruise KR98-01 sent JAMSTEC's two-year-old research vessel Kairei south for a quick but thorough depth survey of the Challenger Deep, 11-13 January 1998, under chief scientist Kantaro Fujioka. Tracking largely along the trench axis of 070°-250° they made five 80-km bathymetric survey tracks, spaced about 15-km apart, overlapping their SeaBeam 2112-004 (which now allowed sub-bottom profiling penetrating as much as 75 m below the bottom) while gaining gravity and magnetic data covering the entire Challenger Deep: western, central, and eastern basins.

The ‘’Kairei’’ returned in May, 1998, cruise KR98-05, with the ROV Kaiko, under the direction of chief scientist Jun Hashimoto with both geophysical and biological goals. Their bathymetric survey from May 14 – 26 was the most intensive and thorough depth and seismic survey of the Challenger Deep performed to date. Each evening, the ROV Kaiko deployed for about four hours of bottom time for biological-related sampling, plus about seven hours of vertical transit time. When the Kaiko was onboard for servicing, the Kairei conducted bathymetric surveys and observations. The Kairei gridded a survey area about 130 km N-S by 110 km E-W. Kaiko made six dives (#71 - #75) all to the same location, (11°20.8' N, 142°12.35' E), near the 10900 m bottom contour line in the western basin.

In 1999, the Kairei revisited the Challenger Deep during cruise KR99-06. The results of the 1998-1999 surveys include the first recognition that the Challenger Deep consists of three “right-stepping en echelon individual basins bounded by the 10500 m depth contour line. The size of [each of] the deeps are almost identical, 14-20 km long, 4 km wide.” They concluded with the proposal “that these three individual elongated deeps constitute the ‘Challenger Deep’, and [we] identify them as the East, Central and West Deep. The deepest depth we obtained during the swath mapping is 10938 m in the West Deep (11°20.34’ N, 142°13.20 E).” The depth was “obtained during swath mapping... confirmed in both N-S and E-W swaths.” Speed of sound corrections were from XBT to 1800 m, and CTD below 1800 m.Gwyncann (talk) 07:42, 22 November 2019 (UTC)


 * I suggest merging your text with what was previously entered. If information from various sources conflicts I suggest simply mentioning that. --Francis Flinch (talk) 09:27, 22 November 2019 (UTC)
 * OK, I'll try, but another survey in 2001 intervenedGwyncann (talk) 05:03, 23 November 2019 (UTC)

In 2002 the Kairei revisited the Challenger Deep 16-25 October 2002, as cruise KR02-13 (a cooperative Japan-US-South Korea research program) with chief scientist Jun Hashimoto in charge; again with Kazuyoshi Hirata managing the ROV Kaiko team. On this survey, the size of the three basins was refined to 6-10 km long by about 2 km wide and in excess of 10850 m deep. In marked contrast to the Kairei surveys of 1998 and 1999, the detailed survey in 2002 determined that the deepest point in the Challenger Deep is located in the eastern basin around 11.371°N, 142.59315°W, with a depth of 10920 m ±5 m, located about 290 m southeast of the deepest site determined by the survey vessel Takuyo in 1984. The 2002 surveys of both the western and eastern basins were tight, with especially meticulous cross-gridding of the eastern basin with ten parallel tracks N-S and E-W less than 250 meters apart. On the morning of 17 October, ROV Kaiko dive #272 began and recovered over 33 hours later, with the ROV working at the bottom of the western basin for 26 hours (vicinity of 11°20.148' N, 142°11.774 E at 10893 m). Five Kaiko dives followed on a daily basis into the same area to service baited landers and other scientific equipment, with dive #277 recovered on 25 October. Traps brought up large numbers of amphipods (sea fleas), and cameras recorded holothurians (sea cucumbers), White polychaetes (bristle worms), tube worms, and other biological species. During its 1998, 1999 surveys, the Kairei was equipped with a Global Positioning System (GPS) satellite-based radionavigation system. The United States government lifted the GPS selective availability in 2000, so during its 2002 survey, the Kairei had access to non-degraded GPS positional services and achieved single digit meter accuracy in geodetic positioning. Gwyncann (talk) 07:34, 23 November 2019 (UTC)

1976 – RV Kana Keoki —  On Leg 3 of the Hawaii Institute of Geophysics' (HIG) expedition 76010303, the 156-foot research vessel Kana Keoki departed Guam primarily for a seismic investigation of the Challenger Deep area, under chief scientist Donald M. Hussong. The ship was equipped with air guns (for seismic reflection soundings deep into the Earth's mantle), magnetometer, gravimeter, 3.5-kHz and 12-kHz sonar transducers, and precision depth recorders. They ran the Deep from east to west, collecting single beam bathymetry, magnetic and gravity measurements, and employed the air guns along the trench axis, and well into the backarc and forearc, from 13-15 March 1976. Thence they proceeded south to the Ontong Java Plateau. All three deep basins of the Challenger Deep were covered, but the Kana Keoki recorded a maximum depth of 7800 m. Seismic information developed from this survey was instrumental in gaining an understanding of the subduction of the Pacific Plate under the Philippine Sea Plate. In 1977, the Kana Keoki returned to the Challenger Deep area for wider coverage of the forearc and backarc.

https://oceanexplorer.noaa.gov/okeanos/explorations/ex1605/background/geology/media/fig1-hires.jpg

Note, the above graphic was first presented in ”International Decade of Ocean Exploration, Progress Report Volume 7, April 1977 to April 1978,” US Dept of Commerce, NOAA, Environmental Data and Information Service, October 1978, p.61 – a US government publication thus no copyright protection. The link is to a government website, thus no copyright protection. Recommend this graphic next to the 1976 Kana Keoki item in Surveys and Bathymetry. I don’t know how but I will try.Gwyncann (talk) 06:25, 24 November 2019 (UTC)

1997 - RV Moana Wave - 23 Aug - 8 Sep 1997    days 235-251  chief scientist Dr. Patricia Fryer, Univ. of Hawaii  Natl Science Foundation  might have missed most of challenger deep. HRMG with MR1

2001 – RV Melville —– Scripps Institution of Oceanography's (SIO) Cook Expedition, Leg 6 with chief scientist Dr. Patricia Fryer of the University of Hawaii, departed Guam on 10 February 2001 for the Challenger Deep for a survey titled “Subduction Factory Studies in the Southern Mariana,” including HMR-1 sonar mapping, magnetics, gravity measurements, and dredging in the Mariana arc region The covered all three basins, then tracked 10 nmi-long lines of bathymetry East-West, stepping northward from the Deep in 12 km sidesteps, covering more than 90 nmi north into the backarc with overlapping swaths from their SeaBeam 2000 12-khz multibeam echosounder and MR1 towed system. They also gathered magnetic and gravity information, but no seismic data. Their primary survey instrument was the MR1 towed sonar, a shallow-towed 11/12-kHz bathymetric sidescan sonar developed and operated by the Hawaii Mapping Research Group (HMRG), a research and operational group within University of Hawaii’s School of Ocean and Earth Science and Technology (SOEST) and the Hawaii Institute of Geophysics and Planetology (HIGP). The MR1 is full-ocean-depth capable, and provides both bathymetry and sidescan data. Leg 6 of the Cook Expedition continued the MR-1 survey of the Mariana Trench backarc from 4 March to 12 April 2001 under chief scientist Sherman Bloomer of Oregon State University.

Adding above Melville 2001 surveys..Gwyncann (talk) 06:51, 25 November 2019 (UTC) HMR-1 sonar mapping, magnetics, gravity measurements, and dredging in the Mariana arc region

2008 – RV Kairei – Cruise KR08-05 Leg 1 and Leg 2 to the central basin but surveyed eastern basin too; ABISMO leg 1; 11000 m class Free Fall Mooring System leg 2. Leg 1 26 May 2008 - 6 June 2008;  Leg 2 7 June - 14 Jun 2008

OK, here's the 2008 Kairei write-up: 2008 – RV Kairei –- In June, 2008 the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) deployed the research vessel Kairei to the area of Guam for cruise KR08-05 Leg 1 and Leg 2. On 3 June 2008, during Leg 1, the Japanese robotic deep-sea probe ABISMO (Automatic Bottom Inspection and Sampling Mobile) reached the bottom about 150 km (93 mi) east of the Challenger Deep, and collected sediment cores and water samples. Upon successful testing to 10000 meters plus, JAMSTEC’ ROV ABISMO became the only operational full ocean depth remotely operated vehicle since the loss of the Kaiko in 2003? until the HROV Nereus was tested to full-ocean depth in 2014?. During ABISMO's deepest dive its manometer measured a depth of 10,258 m (33,655 ft) ±3 m (10 ft) in “Area 1” (vicinity of 12°43’ N, 143°33’ E). Leg 2, under chief scientist Takashi Murashima, operated at the Challenger Deep June 8-9, 2008, testing JAMSTEC’s new full ocean depth “Free Fall Mooring System,” i.e. a lander. The lander was successfully tested twice to 10895 meters depth, taking video images and sediment samplings at 11°22.14 N, 142°25.76’ E, in the central basin of the Challenger Deep.Gwyncann (talk) 06:54, 3 December 2019 (UTC)Gwyncann (talk) 07:05, 5 December 2019 (UTC)

2009 – RV Kilo Moana-  '''Univ of Hawaii ship ROV Nereus from Whoi Dive 10902 m on 31 May 2009  chief scientists Andy bowen WHOI and Patty Fryer U of Hawaii  ten hours on bottom live videoOn 1 June 2009, sonar mapping of the Challenger Deep by the Kongsberg Simrad EM 120 sonar multibeam bathymetry system for deep water (300 – 11,000 metres) mapping aboard the 1,407-ton RV Kilo Moana (mothership of the underwater vehicle Nereus) indicated a depth of 10,971 m (35,994 ft). The sonar system uses phase and amplitude bottom detection, which is capable of an accuracy of 0.2% to 0.5% of water depth across the entire swath.[66][67] Each 1 degree beam width sonar ping expands to cover a circular area about 192 metres (630 ft) in diameter at 11,000 metres (36,089 ft) depth.[68] In 2014 the multibeam bathymetry data of this sonar mapping have yet to be publicly released, so the data are not available for comparisons with other soundings.[69]

Below is the first writeup of the 2009 Kilo Moana surveyGwyncann (talk) 04:46, 28 November 2019 (UTC) In 2002 the Kairei revisited the Challenger Deep 16-25 October 2002, as cruise KR02-13 (a cooperative Japan-US-South Korea research program) with chief scientist Jun Hashimoto in charge; again with Kazuyoshi Hirata managing the ROV Kaiko team. On this survey, the size of the three basins was refined to 6-10 km long by about 2 km wide and in excess of 10850 m deep. In marked contrast to the Kairei surveys of 1998 and 1999, the detailed survey in 2002 determined that the deepest point in the Challenger Deep is located in the eastern basin around 11.371°N, 142.59315°W, with a depth of 10920 m ±5 m, located about 290 m southeast of the deepest site determined by the survey vessel Takuyo in 1984. The 2002 surveys of both the western and eastern basins were tight, with especially meticulous cross-gridding of the eastern basin with ten parallel tracks N-S and E-W less than 250 meters apart. On the morning of 17 October, ROV Kaiko dive #272 began and recovered over 33 hours later, with the ROV working at the bottom of the western basin for 26 hours (vicinity of 11°20.148' N, 142°11.774 E at 10893 m). Five Kaiko dives followed on a daily basis into the same area to service baited landers and other scientific equipment, with dive #277 recovered on 25 October. Traps brought up large numbers of amphipods (sea fleas), and cameras recorded holothurians (sea cucumbers), White polychaetes (bristle worms), tube worms, and other biological species. During its 1998, 1999 surveys, the Kairei was equipped with a Global Positioning System (GPS) satellite-based radionavigation system. The United States government lifted the GPS selective availability in 2000, so during its 2002 survey, the Kairei had access to non-degraded GPS positional services and achieved single digit meter accuracy in geodetic positioning. Gwyncann (talk) 07:34, 23 November 2019 (UTC)

In 2002 the Kairei revisited the Challenger Deep 16-25 October 2002, as cruise KR02-13 (a cooperative Japan-US-South Korea research program) with chief scientist Jun Hashimoto in charge; again with Kazuyoshi Hirata managing the ROV Kaiko team. On this survey, the size of the three basins was refined to 6-10 km long by about 2 km wide and in excess of 10850 m deep. In marked contrast to the Kairei surveys of 1998 and 1999, the detailed survey in 2002 determined that the deepest point in the Challenger Deep is located in the eastern basin around 11.371°N, 142.59315°W, with a depth of 10920 m ±5 m, located about 290 m southeast of the deepest site determined by the survey vessel Takuyo in 1984. The 2002 surveys of both the western and eastern basins were tight, with especially meticulous cross-gridding of the eastern basin with ten parallel tracks N-S and E-W less than 250 meters apart. On the morning of 17 October, ROV Kaiko dive #272 began and recovered over 33 hours later, with the ROV working at the bottom of the western basin for 26 hours (vicinity of 11°20.148' N, 142°11.774 E at 10893 m). Five Kaiko dives followed on a daily basis into the same area to service baited landers and other scientific equipment, with dive #277 recovered on 25 October. Traps brought up large numbers of amphipods (sea fleas), and cameras recorded holothurians (sea cucumbers), White polychaetes (bristle worms), tube worms, and other biological species. During its 1998, 1999 surveys, the Kairei was equipped with a Global Positioning System (GPS) satellite-based radionavigation system. The United States government lifted the GPS selective availability in 2000, so during its 2002 survey, the Kairei had access to non-degraded GPS positional services and achieved single digit meter accuracy in geodetic positioning. Gwyncann (talk) 07:34, 23 November 2019 (UTC)

2009 – RV Kilo Moana –– The Navy-owned research vessel Kilo Moana (T-AGOR 26) is civilian-manned and operated by the University of Hawaii School of Ocean and Earth Science and Technology (SOEST). It is a 186-ft, 1407-ton twin-hulled research vessel equipped with two multibeam echosounders with sub-bottom profiler addons (the 191-beam 12 Khz Kongsberg Simrad EM120 with SBP-1200, capable of accuracies of 0.2%-0.5% of water depth across the entire swath), gravimeter, and magnetometer. Navigation equipment includes the Applanix POS MV320 V4, rated at accuracies of ½-to-2 meters. From May 2 to June 5, 2009, the Kilo Moana hosted the Woods Hole Oceanographic Institution (WHOI) HROV Nereus team for the first operational test of the Nereus in its 3-ton teathered ROV mode. The Nereus team was headed by Dr. Louis Whitcomb of Johns Hopkins University, and Dr. Dana Yoerger and Andy Bowen of WHOI. The University of Hawaii sent two chief scientists: biologist Tim Shank, and geologist Patricia Fryer, to head the science team exploiting the ship’s bathymetry and organizing the science experiments deployed by the Nereus. From Nereus dive #007ROV to 880 m just south of Guam, to dive #010ROV into the Nero Deep at 9050 m, the testing gradually increased depths and complexities of activities at the bottom. Dive #011ROV, on May 31, 2009, saw the Nereus piloted on a 27.8-hour underwater mission, with about ten hours transversing the eastern basin -- from the south wall, northwest to the north wall -- streaming live video. A maximum depth of 10902 m was registered at 11°22.10 N, 142°35.48 E. The Kilo Moana then relocated to the western basin, where a 19.3-hour underwater dive found a maximum depth of 10899 m on dive #012ROV, and on dive #014ROV in the same area (11°19.59 N, 142°12.99 E) encountered a maximum depth of 10176 m. The Nereus was successful in recovering both sediment and rock samples from the eastern and the western basins. The ROV’s final dive was about 80 nmi to the north of the Challenger Deep, in the backarc, where they dove 2963 m at the TOTO Caldera (12°42.00 N, 143°31.5 E). Gwyncann (talk) 06:17, 28 November 2019 (UTC)

2010 – USNS Sumner – On 7 October 2010, further sonar mapping of the Challenger Deep area was conducted by the US Center for Coastal & Ocean Mapping/Joint Hydrographic Center (CCOM/JHC) aboard the 4.762-ton USNS Sumner. The results were reported in December 2011 at the annual American Geophysical Union fall meeting. Using a Kongsberg Maritime EM 122 multibeam echosounder system coupled to positioning equipment that can determine latitude and longitude up to 50 cm (20 in) accuracy, from thousands of individual soundings around the deepest part the CCOM/JHC team preliminary determined that the Challenger Deep has a maximum depth of 10,994 m (36,070 ft) at 11.326344°N 142.187248°E, with an estimated vertical uncertainty of ±40 m (131 ft) at two standard deviations (≈ 95.4%) confidence level.[70] A secondary deep with a depth of 10,951 m (35,928 ft) was located at approximately 23.75 nmi (44.0 km) to the east at 11.369639°N 142.588582°E in the Mariana Trench.[71][72][73][74]

2010 – RV Yokosuka -–The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) returned the research vessel Yokosuka to the Challenger Deep with cruise YK10-16, November 21 - 28 November, 2010. The chief scientist of this joint Japanese-Danish expedition was Hiroshi Kitazato of the Institute of Biogeosciences, JAMSTEC. The cruise was titled: "Biogeosciences at the Challenger Deep: relict organisms and their relations to biogeochemical cycles." The Japanese teams made five deployments of their 11,000-meter camera system (three to 6000 meters – two into the central basin of the Challenger Deep) which returned with 15 sediment cores, video records and 140 scavenging amphipod specimens. The Danish Ultra Deep Lander System was employed by Ronnie Glud et.al. on four casts, two into the central basin of the Challenger Deep and two to 6000 m some 34 nmi west of the central basin. The deepest depth recorded was on 28 November 2010 – camera cast CS5 – 11°21.9810’N, 142°25.8680’E, at a corrected depth of 10889.6 m (the central basin). Gwyncann (talk) 05:45, 5 December 2019 (UTC)

'''2012 -- mermaid -- Deepsea Challenger

2013 – RV Yokosuka -– With JAMSTEC Cruises YK13-09 & YK13-12, the research vessel Yokosuka hosted chief scientist Hidetaka NOMAKI for a trip to New Zealand waters (YK13-09), and the return cruise identified as YK13-12. The project name was QUELLE2013; and the cruise title was: “In situ experimental & sampling study to understand abyssal biodiversity and biogeochemical cycles.” They spent one day on the return trip at the Challenger Deep to obtain DNA/RNA on the large amphipods inhabiting the Deep (--Hirondellea gigas--). Hideki KOBAYASHI (Biogeos, JAMSTEC) and team deployed a lander on 23 November 2013 with eleven baited traps (three bald, five covered by insulating materials, and three automatically sealed after nine hours) into the central basin of the Challenger Deep at 11°21.9082’ N, 142°25.7606’ E, depth 10896 m. After an eight-hour, 46-minute stay at the bottom, they recovered some 90 individual Hirondellea gigas.Gwyncann (talk) 06:40, 5 December 2019 (UTC)

2014 – RV Kairei – Cruise KR14-01 Chief scientiest Hidetaka Nomaki head of Kaiko team Atsumori Miura   Kaiko launcher; ABISMO lander. 6-20 January 2014

2014 – RV Kairei – JAMSTEC deployed the research vessel Kairei to the Challenger Deep again 11-17 January 2014, under the leadership of chief scientist Takuro NUNORA. The cruise identifier was KR14-01, titled: “Trench biosphere expedition for the Challenger Deep, Mariana Trench”. The expedition tested at six stations transecting the central basin, with only two deployments of the “11-K camera system” lander for sediment cores and water samples to “Station C” at the deepest depth, i.e. 11°22.1942’ N, 142°25.7574 E, at 10,903 m. The other stations were investigated with the “Multi-core” lander, both to the backarc northward, and to the Pacific Plate southward. The 11,000-meter capable ROV ABIMSO was sent to 7646 m depth about 20 nmi due north of the central basin (ABISMO dive #21) specifically to identify possible hydrothermal activity on the north slope of the Challenger Deep, as suggested by findings from Kairei cruise KR08-05 in 2008. AMISMO’s dives #20 and #22 were to 7900 meters about 25 nmi north of the deepest waters of the central basin. Italian researchers under the leadership of Laura Carugati from the Polytechnic University of Marche, Italy (UNIVPM) were investigating the dynamics in virus/prokaryotes interactions in the Mariana Trench.

2014 – RV Falkor – Dec 15-21 Schmidt Ocean Institute  four different untethered insturments deployed into trench a total of seven times  Landers Leego  central basin    ARI central basin - LOST   Deep Sound 3 central basin -- NOT Recovered cause implosion  Deep Sound 2 central basin  9000 meters   Leggo 2nd drop 11010 uncorrecte depth central basin  Leggo third drop 11,168 uncorrected depth in eastern basin  Deepsound 2 2nd drop eastern basin 9000 meters.

2014 – RV Falkor – From 16-19 December 2014, the Schmidt Ocean Institute’s research vessel Falkor, under chief scientist Douglas Bartlett from the Scripps Institution of Oceanography, deployed four different untethered instruments into the Challenger Deep for seven total releases. Four landers were deployed on 16 December into the central basin: the baited video-equipped lander Leggo for biologics; the lander ARI to 11°21.5809 N, 142°27.2969 for water chemistry; and the probes Deep Sound 3 and Deep Sound 2. Both Deep Sound probes recorded acoustics floating at 9000 meter depth, until Deep Sound 3 imploded at the depth of 8620 meters (about 2200 meters above the bottom) at 11°21.999 N, 142°27.2484 E. The Deep Sound 2 recorded the implosion of Deep Sound 3, providing a unique recording of an implosion within the Challenger Deep depression. In addition to the loss of the Deep Sound 3 by implosion, the lander ARI failed to respond upon receiving its instruction to drop weights, and was never recovered. On 16/17 December, the Leggo was returned to the central basin baited for amphipods. On the 17th, the Falkor relocated 17 nms eastward to the eastern basin, where they again deployed both the Leggo (baited and with its full camera load), and the Deep Sound 2. Deep Sound 2 was programmed to drop to 9000 m and remain at that depth during its recording of sounds within the trench. The Leggo landed at 11°22.11216 N, 142°35.250996 at 10,929 m (!) (from pressure readings) on 19 December. The Leggo returned with good photography of amphipods feeding on the lander’s mackerel bait and with sample amphipods. The Falknor departed the Challenger Deep on 19 December en route the Serina Deep. The Falkor had both a Kongsberg EM302 and EM710 multibeam echosounder for bathymetry, and a C-Nav 3050 capable of calculating geodetic positioning within ten centimeter (10% of one meter)!!.

'2015 – USCGC Sequoia – From 10-13 July 2015, the Guam-based US Coast Guard Cutter Sequoia (WLB 215) hosted a team of researchers under chief scientist Robert P. Dziak from the National Ocean and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory (PMEL), the University of Washington, and Oregon State University in deploying PMEL's "Full-Ocean Depth Mooring," a 45-meter-long moored deep-ocean hydrophone and pressure sensor array into the western'' basin of the Challenger Deep. A 6-hour descent into the western basin anchored the array at 10854.7 +/- 8.9 meters of water depth, at 11 20.127 N, 142 12.0233 E, about 1 km northeast of the USNS Sumner's deepest depth recorded in 2010. After 15 weeks, the moored array was recovered 2-4 Nov 2015. "Observed sound sources included earthquake signals (T phases), baleen and odontocete cetacean vocalizations, ship propeller sounds, airguns, active sonar and the passing of a Category 4 typhoon." The science team described their results as "the first multiday, broadband record of ambient sound made at Challenger Deep, as well as only the fifth direct depth measurement." Gwyncann (talk) 21:52, 21 December 2019 (UTC) NOTE please, inconsistency in dates in original indicates error. In subpara "Mooring Deployment and Recovery" ref states "During July 20-23, the mooring was deployed..." Next page subpara "Full Ocean Depth Hydrophone" ref states that "...the hydrophone operated successfully at full bandwidthe (32 kHz) for 24 days (July 13 - August 6, as planned)..." Earlier statement that the array was deployed July 20-23 seems to be an error for "July 10-13"- which is how I show itGwyncann (talk) 21:52, 21 December 2019 (UTC)

2016 – RV Sonne – In November 2016 sonar mapping of the Challenger Deep area was conducted by the Royal Netherlands Institute for Sea Research (NIOZ)/GEOMAR Helmholtz Centre for Ocean Research Kiel aboard the 2.566-ton Deep Ocean Research Vessel RV Sonne. The results were reported in 2017. Using a Kongsberg Maritime EM 122 multibeam echosounder system coupled to positioning equipment that can determine latitude and longitude the team determined that the Challenger Deep has a maximum depth of 10,925 m (35,843 ft) at 11°19.945′N 142°12.123′E (11.332417°N 142.20205°E), with an estimated vertical uncertainty of ±12 m (39 ft) at one standard deviation (≈ 68.3%) confidence level. The analysis of the sonar survey offered a 100 metres (328 ft) by 100 metres (328 ft) grid resolution at bottom depth, so small dips in the bottom that are less than that size would be difficult to detect from the 0.5 by 1 degree sonar-emissions at the sea surface. Each 0.5 degree beam width sonar ping expands to cover a circular area about 96 metres (315 ft) in diameter at 11,000 metres (36,089 ft) depth.[75] The horizontal position of the grid point has an uncertainty of ±50 to 100 m (164 to 328 ft), depending on along-track or across-track direction. This depth (59 m (194 ft)) and position (about 410 m (1,345 ft) to the northeast) measurements differ significantly from the deepest point determined by the Gardner et al. (2014) study.[76][77][78] The observed depth discrepancy with the 2010 sonar mapping and Gardner et al 2014 study are related to the application of differing sound velocity profiles, which are essential for accurate depth determination. RV Sonne used CTD casts to near the bottom of the Challenger Deep that were used for sound velocity profile calibration and optimization. Likewise the impact of using different projections, datum and ellipsoids during data acquisition can cause positional discrepancies between surveys.[2]

'''2015-2017 --three cruises R/V Dayang 37-II (DY37II), RV Tansuo 01 (TS01) and RV Tansuo 03 (TS03) June–July of 2016, June–August of 2016 and January–March ofchinese - Cruises 2016S1 and 2016S2 cruises took place during the summer of 2016, while 2015W and 2016W cruises took place during the winters of 2015 and 2016 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6081482/  four cruises by the Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences. The four cruises are labelled as 2015W, 2016S1, 2016S, and 2016W, respectively.

2016 - ROV Haidou-1 - On 23 May 2016 the Chinese submersible Haidou-1 dove to a depth of 10,767 m (35,325 ft) in the Mariana Trench. This autonomous and remotely operated vehicle has a design depth of 11,000 m (36,089 ft).[47]

Here are the first of the Chinese surveys of the Challenger Deep. There are quite a few and difficult to put together from almost entirely newspaper reportingGwyncann (talk) 20:44, 1 December 2019 (UTC) 2016 – RV Xiangyanghong 09 –– The 3536-ton research vessel HiangYangKong 09 deployed on Leg II of the 37th China Cruise Dayang {DY37II) sponsored by the National Deep Sea Center, Qingdao and the Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences (Sanya, Hainan), to the Challenger Deep western basin area (11°22′ N, 142°25′ E) 4 June-12 July 2016. As the mother ship for China’s manned deep submersible Jiaolong, the expedition carried out an exploration of the Challenger Deep to investigate the geological, biological, and chemical characteristics of the hadal zone. The diving area for this leg was on the southern slope of the Challenger Deep, at depths from about 6300 m to 8300 m. The submersible completed nine manned dives on the northern backarc and south area (Pacific plate) of the Challenger Deep to depths from 5500 to 6700 m. During the cruise, the Jiaolong regularly deployed gas-tight samplers to collect water near the sea bottom. In a test of navigational proficiency, the Jiaolong used an Ultra-Short Base Line (USBL) positioning system at a depth more than 6600 m. to retrieve sampling bottles. Gwyncann (talk) 20:44, 1 December 2019 (UTC)

2016 - RV Tansuo 01 ––  From 22 June -12 August 2016 (cruise 2016S2), the Chinese Academy of Sciences’ 6250-ton submersible support ship Tansuo 1 (meaning: to explore) on her maiden voyage deployed to the Challenger Deep from her home port of Sanya, Hainan Island. On July 12, 2016, the ROV Haidou-1 dove to a depth of 10,767 m (35,325 ft) in the Challenger Deep, making China the third country after Japan (ROV Kaiko), and the US (HROV Nereus), to deploy a full-ocean-depth ROV. The Haidou-1 is an autonomous and remotely operated vehicle with a designed maximum depth of 11,000 m (36,089 ft). They also cast a free-drop lander, 9000-meter rated free-drop ocean-floor seismic instruments (deployed to 7731 meters), obtained sediment core samples, and collected over 2000 biological samples from depth ranging from 5000 - 10000 meters. The Tansuo 01 operated along the 142°30.00' longitude line, about 30 nmi east of the earlier DY37II cruise survey (see Xiangyanghong 09 above) Gwyncann (talk) 21:30, 1 December 2019 (UTC)

2016 -- RV Shyian 3 -- In December 2016, the Chinese Academy of Sciences (CAS) 3,300-ton research vessel Shiyan 3 deployed 33 broadband seismometers onto both the backarc northwest of the Challenger Deep, and onto the near southern Pacific Plate to the southeast, at depths of up to 8137 meters. The $12 million Chinese-U.S. initiative, led by co-leader Jian Lin of Woods Hole Oceanographic InstitutionWoods Hole, was engaged in a 5-year effort (2017-2021) to image in fine detail the rock layers in and around the Challenger Deep.

2016 – RV Zhang Jian -- The newly launched 4800-ton research vessel and mothership for the Rainbow Fish series of deep submersibles, the Zhang Jian departed Shanghai on December 3. Their cruise was to test three new deep-sea landers, one unmanned search submersible and the new Rainbow Fish 11000-meter manned deep submersible, all capable of diving to 10,000 meters. From December 25 to 27, three deep-sea landing devices descended into the trench. The first Rainbow Fish lander took photographs, the second took sediment samples, and the third took biological samples. All three submersibles reached over 10,000 meters, and the third device brought back 103 amphipods. Cui Weicheng, director of Hadal Life Science Research Center at Shanghai Ocean University, led the team of scientists to carry out research at the Challenger Deep in the Mariana Trench. The ship is part of China’s national marine research fleet but is owned by a Shanghai marine technology company.

2017 – RV Tansuo-1 –- 14 January - 23 March 2017 Cruise #TSO3? #2016W?? –– the Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences sponsored the Tansuo-1 return to the Challenger Deep. They placed four or more CTD casts into the central and eastern basins of the Challenger Deep, as part of the World Ocean Circulation Experiment (WOCE). blue color on chart

2017 – RV Xiangyanghong 09 -- Cruise 6 February – 23 June 2017. The deep submersible ROV Jiaolong‘s mother ship Xiangyanghong 09 returned to its home port at the National Deep-Sea Center, Chinese Academy of Sciences, in Qingdao, Shandong province, on 23 June, completing China’s 38th oceanic expedition and concluding the submersible ROV Jiaolong’s five-year trial run. During the 138-day expedition that began on 6 February, the mother ship sailed nearly 21,120 miles to the South China Sea and the north-western Indian and north-western Pacific oceans, while Jiaolong conducted 30 dives. Jiaolong will now receive a year-long overhaul and a technical upgrade before starting its formal operating period. Researchers from the State Oceanic Administration, Ministry of Education, the Chinese Academy of Sciences and China Geological Survey used the Jiaolong to collect 1,377lb of seabed rocks, 1,312 gallons of seawater and 2,115 marine creatures. The Jiaolong made five dives each in the Mariana Trench, the world’s deepest known trench, and Yap Trench, both in the western Pacific Ocean. These operations have enabled scientists to better understand the trenches’ geochemical and biological conditions, according to the news release. https://www.telegraph.co.uk/china-watch/technology/chinas-deep-sea-submersible/

2017 - RV Kexue 3 –– March 2017. Water samples were collected at the Challenge Deep from 11 layers of the Mariana Trench in March 2017. Seawater samples from 4 to 4000 m were collected by Niskin Bottles mounted to a Seabird SBE25 CTD (instrument)CTD s; whereas water samples at depth of 6050 and 8320 m were collected by a self-designed acoustic-controlled full ocean depth water samplers. In this study, scientists studied the RNA of pico- and nano-plankton from the surface to the hadal zone.

2017 – Tansuo 01 ––  From 16 August to 3 October, 2017 the manned deep submersible Shenhai Yongshi completed 28 test dive tests during a 49-day expedition with its mother ship, the Tansuo 01, reaching its maximum depth of 4,500 meters during the test dives (location unknown). The Shenhai Yongshi (meaning: Deep-Sea Warrior) was officially delivered to the Chinese Academy of Sciences in Sanya, Hainan province, in December 2017.

2018 – RV Dayang 1 –- the Qingdao–based 5600-ton research ship Dayang 1 (meaning: ocean 1), operated by the China Ocean Mineral Resources R&D Association, supported the 11,000-meter rated ROV Hailong in March/April 2018 in early diving trials. The Hailong reached a planned depth of 2605 meters. Workup tests will continue for a scheduled full depth test in 2021. Also supported was the ROV Qianlong No. 2. This was the Dayang’s 19th cruise.

2018 – RV Shen Kuo – On her maiden voyage of the 2150-ton twin-hulled scientific research vessel Shen Kuo (also Shen Ko, Shen Quo), departed Shanghai on 25 November 2018 and returned 8 January 2019. They operated in the Mariana Trench area and on 13 December tested a system of underwater navigation at a depth exceeding 10,000 metres, during a field trial of the Tsaihungyuy (ultra-short baseline) system. Project leader Tsui Veichen stated that, with the tsaihungyuy equipment at depth, it was possible to obtain a signal and determine exact geolocations. The research team from Shanghai Ocean University and Westlake University was led by Cui Weicheng, director of Shanghai Ocean University’s Hadal Science and Technology Research Center. The equipment to be tested includes a manned submersible and two deep-sea landing devices, all capable of diving to depths of 10,000 meters, as well as a deep-sea buoy that can go to 4,500 meters. They took photographs and obtained samples from the trench, including water, sediment, macro-organisms and micro-organisms. “If we can take photos of fish more than 8,145 meters under water,” said Cui, “we will break the current world record. We will test our new equipment including the landing devices. They are the second generation. The first generation could only take samples in one spot per dive, but this new second generation can take samples at different depths in one dive. We will also test the ultra short baseline acoustic positioning system on the manned submersible, the future of underwater navigation.”

OK - I'm done with the Chinese surveys for a while. Someone with the ability to turn up Chinese language sources is needed to provide better info on these surveys.Gwyncann (talk) 23:33, 1 December 2019 (UTC) The situation is that on 16 March 2016, China approved its 13th Five-Year Plan listing deep-sea scientific exploration as one of the key projects in its five-year plan for 2016-2020. The scale of Beijing’s investment now dwarfs that of any other country, including the United States. When it was set up in 2012, China’s National Fleet comprised just 19 vessels, by the end of 2019 it had expanded to 56 ships. This number does not include five large hulls owned by the China Geologic Survey. The fleet continues to expand. The Chinese government is also funding development of a suite of other research platforms: manned submersibles, AUVs, and surface and subsurface moorings. China’s expanding investment contrasts markedly with declining government support for marine science in the U.S. Gwyncann (talk) 23:33, 1 December 2019 (UTC)

In 2017, for the first time, China has overtaken the United States in terms of the total number of science publications, according to statistics compiled by the US National Science Foundation (NSF). China published more than 426,000 studies in 2016, or 18.6% of the total documented in Elsevier’s Scopus database. That compares with nearly 409,000 by the United States. Gwyncann (talk) 23:33, 1 December 2019 (UTC)

Thus it should be no surprise that Chinese expeditions to the Mariana Trench and the Challenger Deep expanded markedly since 2015. Available information is fragmentary in English, and these surveys should be strengthed by someone with Chinese language facility.Gwyncann (talk) 23:33, 1 December 2019 (UTC)

2017 - RV Shinyo Maru -- Tokyo University for Marine Science and Technology dispatched the research vessel Shinyo Maru to the Challenger Deep 20 January - 5 February 2017 with baited traps for capture of fish and other macrobiology in the Deep. On 29 January they recovered photography and samples of a new species of snailfish from 7581 meters, newly designated "Pseudoliparis swirei".

2017 – RV Kairei – Cruise KR17-08C  Chief scientist Takashi Murashima  Test 11000 m ROV UROVIIK   UROVIIK Lost during mission. 5-25 May 2017

2017 - Kairei -- JAMSTEC deployed the research vessel Kairei to the Challenger Deep in May 2017 for the express purpose of testing the new full-ocean depth ROV UROV11K (Underwater ROV 11000-meter-capable), cruise KR 17-08C, under chief scientist Takashi MURASHIMA. The cruise title was: “Sea trial of a full depth ROV UROV11K system in the Mariana Trench.” The UROV11K carried a new 4K High Definition video camera system, and new sensors to monitor the hydrogen-sulfide, methane, oxygen, and hydrogen content of the water. Unfortuately, onUROV11K’s ascent from 10899 meters (about 11°22.30’N 142°35.8 E, in the eastern basin)  on May 14, 2017 the ROV’s buoyancy failed at 5320 meters (slow leak?), and all efforts to retrieve the ROV were unsuccessful. The rate of descent and drift is not available, but the ROV apparently bottomed to the east of the deepest waters of the eastern basin (as revealed by the ship's maneuvering on May 14). Murashima then directed the Kairei to a location about 35 nmi east of the eastern basin of the Challenger Deep to test a new “Compact Hadal Lander” which made three descents to depths from 7498 to 8178 m for testing the Sony 4K camera and for photography of fish and other macro-biologics. Gwyncann (talk) 23:13, 7 December 2019 (UTC)

2019 – RV Sally Ride -- In early November 2019, physical oceanographer Hans van Haren from the Royal Netherlands Institute for Sea Research (NIOZ), and his team recovered their seven-kilometer long mooring line of temperature and current meters from the Challenger Deep. The array had been deployed in November 2016 from the German RV Sonne (see above). The moored instrumentation was intended to remain in the Challenger Deep for 1 to 1½ years, but eventually remained under water for nearly three years. An attempt to recover the array in late 2018 by the RV Sonne was unsuccessful. In November 2019, the 3043-ton research vessel Sally Ride (AGOR 28), Navy-owned, civilian-crewed, and managed by the Scripps Institution of Oceanography (SIO), was made available to the Dutch team for another attempt to recover the array. They were successful and found that only 15 of the 400 sensors had mechanical problems. At least 1.5 years of useful data were obtained, which is more than expected. Gwyncann (talk) 07:39, 8 December 2019 (UTC)

2019 - Pressure Drop -- DSV Limiting Factor

Has the 2019 RV Sally Ride Expedition reported a depth of 10,925 m (35,843 ft) in the western basin?--Francis Flinch (talk) 16:29, 22 December 2019 (UTC)

Descents
I'm going to start working on the Descents section of the Challenger Deep article. Here is a start -- ran out of time and now going to bed.

2019 – Five Deeps Expedition / DSV Limiting Factor


The Five Deeps Expedition visited the deepest points of all five of the world's oceans from December 18, 2018 through August 24, 2019 and included at least one solo dive into each trench by expedition leader Victor L. Vescovo. A sixth dive was added to ascertain if the Tonga Trench was deeper than the Challenger Deep (it was not). The targeted solo dives were completed as follows:

.Δ. Puerto Rico Trench (Atlantic Ocean) -- December 18, 2018 -- 8,376 meters

.Δ. South Sandwich Trench -- (Southern Ocean) -- February 4, 2019 -- 7,434 meters

.Δ. Java Trench -- (Indian Ocean) -- April 5, 2019 -- 7,192 meters

.Δ. Challenger Deep (Pacific Ocean) -- April 28, 2019 -- 10,924 meters (plus three more dives 1-4 May; and a fifth into the Sirena Deep on May 8

.Δ. Horizon Deep, Tonga Trench -- (South Pacific) -- June 5, 2019 -- 10,823 meters

.Δ. Molloy Deep (Arctic Ocean) -- August 24, 2019 -- 5,550 meters Gwyncann (talk) 07:30, 25 December 2019 (UTC)

List of Descents
Here is the list of descents to the bottom of the Mariana Trench (and specifically Challenger Deep and Sirena Deep) (with count of individuals to have reached the bottom), current through March 01, 2021. See now List of people who descended to Challenger Deep. My numbering here omits Dr. Jamieson's dive to Sirena Deep to keep the CD ordinals congruent.

1960
1 & 2. Jacques Piccard and Don Walsh (Trieste) 23 JAN 1960 10,912m

2012
3. James Cameron (Deepsea Challenger)(solo) 26 MAR 2012 10,908m

2019
4. Victor Vescovo (Limiting Factor)(solo x2) 28 APR 2019 and 01 MAY 2019 - Eastern Pool 10,928m** (WR) 5 & 6. Patrick Lahey & Jonathan Struwe (Limiting Factor)(Triton Submarines President and DNV_GL surveyor for unlimited depth certification) 03 MAY 2019 - Eastern Pool 10,927m 5 & 7. Patrick Lahey & John Ramsay (Limiting Factor)(Triton Submarines President and Design Engineer) 05 MAY 2019 - Center Pool 4 & X. Victor Vescovo and Dr. Alan Jamieson (Limiting Factor)(Five Deeps Leader and Five Deeps Chief Scientist) 07 MAY 2019 - Sirena Deep, to the east of Challenger Deep in the Mariana Trench, part of same sequence of dives but not Challenger Deep.

2020
4 & 8. Victor Vescovo and Kathryn Sullivan** (Limiting Factor)(Ring of Fire Leader and Astronaut/NOAA Administrator) 07 JUN 2020 ** First woman to reach bottom of Challenger Deep 4 & 9. Victor Vescovo and Vanessa O'Brien (Limiting Factor)(Ring of Fire Leader and Global Explorer) 12 JUN 2020 ** Second woman to reach bottom of Challenger Deep - 3.5 hour bottom time, 10,914m, fifth dive for Victor Vescovo. O'Brien is the only woman to summit Everest and dive to Challenger Deep. 4 & 10. Victor Vescovo and John Rost (Limiting Factor)(Ring of Fire Leader and Global Explorer) 14 JUN 2020 ** Four hours and seven minutes at depth; 2 miles of transit at bottom (new records). 4 & 11. Victor Vescovo and Kelly Walsh (Limiting Factor)(Ring of Fire Leader and son of Don Walsh, first (with Piccard) to voyage to the bottom of the ocean)(Western Pool, Challenger Deep). 19 JUN 2020. 4 & 12. Victor Vescovo and Ying-Tsong "YT" Lin (Limiting Factor)(Ring of Fire Leader and underwater acoustic physicist)(Central Pool). 21 JUN 2020 First Taiwanese to bottom of the ocean. Dive took place after the solar eclipse. 4 & 13. Victor Vescovo and Jim Wigginton, 26 JUN 2020 (Ring of Fire Leader and Global Explorer)(Oldest diver to Challenger Deep).

2021 (ongoing)
4 & 14. Victor Vescovo and Richard Garriott (Limiting Factor)(Ring of Fire 2 Expedition Leader and Astronaut/Explorer). 01 MAR 2021. Because of my association with Triton Submarines, I do not materially edit these articles directly.--Brad Patrick (talk) 13:44, 8 June 2020 (UTC)

Sponsorships in Caladan Oceanic's 2020 Dive Series
I am actually the owner and diver of the Limiting Factor, and there is a bit of inaccurate reporting about the nature of some of the divers that made the trip down with me. The people that I have invited down in my submersible are a combination of scientists as well as people I have known from the adventuring community, or those promoting phlianthropic causes. I also have on the docket a journalist who I thought would be appropriate, for example. The cost of operating the while system (ship, sonar, submersible) is expensive, and I do not have unlimited funds. Therefore, I sought sponsors for this year's expedition, which Eyos expedition marketed for me for people they thought might be interested. To characterize the dives as "tourist" dives is not really accurate from my perspective - everyone in the submersible was trained far more than any tourist, including some like Kathy Sullivan and Vanessa O'Brien, who actually attended a manufacturer's course to operate the submersible's manipulator arm (no tourist would be required to do that). Some, who could afford it and where I insisted, contributed funds to the program as expedition sponsors - which is a better and more accurate term. In the sub, they have -all- assisted me with the workload of navigation and mapping, as well as locating landers on the bottom. How certain media have apparently, pejoratively characterized certain divers is not really fair to them, so I would respectfully suggest replacing one footnote in particular with one that is, I believe, more fair and accurate. I would replace footnote 144 with this reference instead: https://news.sky.com/story/vanessa-obrien-british-american-explorer-becomes-first-woman-to-reach-earths-highest-and-lowest-points-12010201 or https://metro.co.uk/2020/06/16/female-explorer-becomes-first-reach-highest-lowest-points-planet-reveals-what-was-like-journeying-4-hours-ocean-floor-12857647/, both of which are more well-known (and I believe more blaanced) references than the original. I submit this for consideration from the editing community and appreciate any feedback. Vlvescovo (talk) 01:02, 23 June 2020 (UTC)