Talk:Volcanic ash

2nd Paragraph of atmospheric effects
The second paragraph of atmospheric effects is completely wrong, according to the current best scientific knowledge, and does not reflect any of the understanding of volcanic dynamics learned since the early 80's. Volcanic ash only has a residence time in the stratosphere of a few months, and has been found not to be responsible for the long term climatic effects. Volatiles, specifically SO2 have a much longer residence time in the stratosphere, where they form aerosols/ice particles which are the source of the long term climatic effects, not fine ash particles which are glass and crystal fragments. Good references to use:

Sigurdsson, H., 1982, Volcanic pollution and climate--the 1783 Laki eruption: American Geophysical Union, EOS Transactions, v. 10 August 1982, p. 601-602.

Rampino, M. R., and Self, S., 1982, Historic eruptions in Tambora (1815), Krakatau (1883), and Agung (1963), their stratospheric aerosols, and climatic impact: Quaternary Research, v. 18, p. 127-143.

Self, S., Zhao, Jing-Xia, Holasek, R.E., Torres, R.C., and King, A.J., 1996, The atmospheric impact of the 1991 Mount Pinatubo eruption, in Newhall, C.G., Punongbayan, R.S. (eds.), 1996, Fire and mud: Eruptions and lahars of Mt. Pinatubo, Philippines, Philippine Institute of Volcanology and Seismology, Quezon City and University of Washington Press, Seattle, 1126 p.

McGee, K.A., Doukas, M.P., Kessler, R. and Gerlach, T., 1997, Impacts of volcanic gases on climate, the environment, and people: U.S. Geological Survey Open-File Report 97-262, 2 p. Geo-editing (talk) 18:41, 20 April 2010 (UTC)
 * Thank you for your suggestion. When you believe an article needs improvement, please feel free to make those changes. Wikipedia is a wiki, so anyone can edit almost any article by simply following the  link at the top. The Wikipedia community encourages you to be bold in updating pages. Don't worry too much about making honest mistakes—they're likely to be found and corrected quickly. If you're not sure how editing works, check out how to edit a page, or use the sandbox to try out your editing skills.  New contributors are always welcome. You don't even need to log in (although there are many reasons why you might want to).  Thegreatdr (talk) 18:46, 20 April 2010 (UTC)

Thanks, but I can't edit the page as it is semi-protected, and I don't want to just randomly find 10 edits to do and wait 4 days, simply to edit this page, I think this is a major flaw in this page, which is probably heavily accessed right now. —Preceding unsigned comment added by Geo-editing (talk • contribs) 18:56, 20 April 2010 (UTC)
 * There is a way around this. You can create a version of the section you wish to edit as an offshoot of your wikipedia page, with the appropriate referencing, then one of us can simply copy and paste it into the article.  Since you're just talking about one paragraph, this should be easy to do.  Thegreatdr (talk) 19:04, 20 April 2010 (UTC)

Ok, done. http://en.wikipedia.org/wiki/User_talk:Geo-editing  the whole second paragraph of climatic effects  on this volcanic ash page should be deleted. I have posted a small paragraph on my page to take that place, but further elaboration should have it's own wiki page. —Preceding unsigned comment added by Geo-editing (talk • contribs) 19:34, 20 April 2010 (UTC)

Bishops rings are also caused by sulfur aerosols, not by volcanic ash. I just edited the Bishop rings wiki page to reflect this, can the Bishop ring reference be removed from the atmospheric effects subsection as well, please? Geo-editing (talk) 19:50, 20 April 2010 (UTC)

One more minor quibble, since I can't edit the page directly. The abstract for the article I linked says that stratospheric S-aerosols have an e-folding residence time of 1 year, it is misleading to rewrite that for the wikipedia to page to drop the e-folding phrasing, but keep in the residence time of 1 year. E-folding time is the time it takes to drop to 1/e, ~1/2.7 of the initial value; for a major volcanic eruption, half of the original aerosols are still quite a lot and still exert an atmospheric effect, if you look at the cooling for major eruptions of the last centry it continues for 2-3 years. The text I suggested referenced a residence time beyond the 1 year efolding time of the abstract, to take into account the discussion of aerosol persistance in the body of the article, the known long term cooling effects, and to simplify the terminology for a reader who doesn't understand the efolding meaning. I'd suggest that my original phrasing be retained, or the e-folding phrasing of the abstract be retained. Geo-editing (talk) 21:39, 20 April 2010 (UTC)
 * It looks like your suggestions have been added. Thanks for the input.  Thegreatdr (talk) 03:30, 21 April 2010 (UTC)

Increased Fertility
Shouldn't there be some info on the fact that soil which contains volcanic ash is generally very fertile for agriculture? Don't know enough about it myself but seems relevant. Lebanese blond 09:55, 8 November 2007 (UTC)
 * bump. An entire article should be made for volcanic related fertility, both for ash, lava, and different types of volcanoes and lava — Preceding unsigned comment added by 191.82.17.145 (talk) 20:06, 2 November 2021 (UTC)

Article improvement
For a five year old article, this article was in bad shape. Added inline references and a reference section, convert templates, as well as more detail to the body of the article. The lead wasn't constructed appropriately per wikipedia standards, so a significant portion of it was moved into the body under characteristics, and rewritten to represent what lies within the article. Much of what was written with the body of the article was in decent shape...it just needed a bit of rearranging to follow more fluidly. Thegreatdr (talk) 17:40, 23 January 2008 (UTC)

Good article assessment
I am putting this article on hold in order to give the editors a chance to address the following issues:

Good article nomination on hold
This article's Good Article promotion has been put on hold. During review, some issues were discovered that can be resolved without a major re-write. This is how the article, as of February 6, 2008, compares against the six good article criteria:


 * 1. Well written?: Fail: It is clear as far as it goes, but a bit choppy, does not "flow."  No glaring errors in spelling, punctuation or grammar, just feels like there are no transitions, just one fact jumping to another with some organization, but earlier versions of the article actually had better "plain English" explanations and descriptive passages.  The information is good as far as it goes, but hard to read the article and concentrate with the disjointed nature of the narrative
 * Transitions have been added, and the text has been edited to flow smoother. If any glaring errors remain in regards to this note, please provide examples so they can be fixed.  Thegreatdr (talk) 13:17, 8 February 2008 (UTC)
 * 2. Factually accurate?: Pass
 * 3. Broad in coverage?: Fail: Article is a good start, but not really broad in coverage, it promises much but does not deliver.  For example, the lead promises more on the formation of ash without going on to explain it in more depth.  The lead also discusses the ecological aspects of an ashfall but does not significantly expand on this below.  The information on the aviation hazards seems out of proportion to the other dangers to human health and to ground-based machinery.
 * Ash is a fairly simple thing to define, which probably explains the lack of too much additional detail. Where in the lead is a statement made that is not supported in the article below?  If you let us know, we can fix it.  Thegreatdr (talk) 13:18, 8 February 2008 (UTC)
 * 4. Neutral point of view?: Pass
 * 5. Article stability? Fail, a ton of work has been done, but much of it with in a two week period. Has been changed dramatically.  Would like to see it sit for a bit to note what other editors who have worked on it think.
 * Not really much we can do about this other than leave the article alone, which is not possible considering the comments left above. Thegreatdr (talk) 13:18, 8 February 2008 (UTC)
 * 6. Images?: Pass -- lovely images

Please address these matters soon and then leave a note here showing how they have been resolved. After 48 hours the article should be reviewed again. If these issues are not addressed within 7 days, the article may be failed without further notice. Thank you for your work so far.
 * So, what's wrong and needs to be fixed? All I see are pass remarks.  Thegreatdr (talk) 01:24, 6 February 2008 (UTC)
 * Ok...that spells it out more thoroughly. Thanks for comments.  Thegreatdr (talk) 01:51, 6 February 2008 (UTC)


 * Sorry about the delay, I load the template and then reedit it. I remember Mt. St. Helens eruption, the article is interesting.  Hope you can expand it out, but if you can't now, you can always renominate later.  Montanabw (talk) 00:16, 8 February 2008 (UTC)

Let me know what you think of the changes. Even after checking several sources, I can't see a way of expanding the definition/creation of ash, since it is a simple process. Volcanic eruptions create ash when their shock waves and resultant heat shatter rock and create fine particles of glass. I tried to reword the article to be more readable. Thegreatdr (talk) 17:16, 9 February 2008 (UTC)


 * No problem I was off wiki a couple of days myself. I think you have made some good improvements, though in doing so you may have also removed some useful material too, the trick is wordsmiting so it all flows together.  I couldn't quite get a handle on what exactly was bugging me, even after the changes, so I asked another reviewer to give it a peek and he provided the following additional thoughts, based on the article as it sits today.  I think I was stuck that it was a bit short, but short alone is not a problem, I think it seems a little choppy yet and just needs some transitional phrasing here and there.  Here is the other reviewers take on it, I agree with his areas for improvement:  Montanabw (talk) 02:36, 13 February 2008 (UTC)

"Here's my eval:
 * The lead should be in two paragraphs, it's too long to be in one grammatically and in terms of readability.
 * It has now been separated into two paragraphs. Thegreatdr (talk) 12:51, 13 February 2008 (UTC)
 * WP:MOS dictates that an article should have a single lead image, usually forced to 250px (unlike the rest of the article, which ideally should not force thumb size). It also prohibits stacking images on top of one another in a row on the right, like the lead images currently do. Pick one lead image and stick with it. The same issue is going on in Atmospheric effects. The solution in the case of stacked images in the body is to have alternating left-right alignment (or simply move images down so there is space between them. Anyway, I'm sure you're competent handling a fix on this.
 * I've moved the second image out of the lead. Thegreatdr (talk) 12:51, 13 February 2008 (UTC)
 * If I remember right WP:CITE requires that exact numerical figures such as stats and other things have in-line citations. Precise numbers stuff like that are almost always required to be cited in GAs, so in Composition were it defines ash as being "less than 2 millimetres...", there needs to be a direct in-line citation.
 * Same thing as above, "as only 100 millimetres" needs a cite."
 * The citation for the 100 mm line is the same as the 300 mm line. The 2 mm line is cited as well, just below after another line.  Did you want multiple consecutive lines cited with the same reference, individually?  I've done this in the case of the 2 mm line, because it was more than one sentence away from the last use of this reference.  Thegreatdr (talk) 10:31, 13 February 2008 (UTC)

Other than that, I do think it's ready to be GA. It's short, but broad and fairly comprehensive.


 * I think you are there, give me a bit of time to run over to the GA pages and get the right templates to make the required changes. (I'm not as anal about "cite every last fact, even if it means saying "Id." a dozen times as some reviewers). I did an article once where someone was fact tagging sentences and so I just added a  comment that said something like "citation covers entire preceding paragraph."  Seemed to settle the matter.   Montanabw (talk) 17:36, 15 February 2008 (UTC)


 * You passed. Congrats!   Montanabw (talk) 20:03, 15 February 2008 (UTC)

Ash Formation
There are three mechanisms of ash formation: gas release under decompression causing magmatic eruptions; thermal contraction from chilling on contact with water causing phreatomagmatic eruptions and ejection entrained particles during steam eruptions causing phreatic eruptions (Heiken & Wohletz 1985, volcanic ash). I feel that this information should be included, but i am not familiar enough with the referencing system to put it in without screwing it up, and i also dont want to tear apart someone elses text and possibly get a Good Article down graded

The full reference is; Heiken, G. & Wohletz, K. 1985. Volcanic Ash. University of California Press, Berkeley. —Preceding unsigned comment added by Russjass (talk • contribs) 19:23, 14 May 2008 (UTC)
 * Okay put it in and references still look good Russjass (talk) 15:37, 18 May 2008 (UTC)

Chichester
Ash? Or just a photo with heavy colour bias? &mdash; RHaworth (Talk | contribs) 18:47, 7 April 2009 (UTC)
 * I agree, I would guess the color is fairly accurate on the Tate Collection website. Besides, I'm not sure the painting adds much to the topic of volcanic ash. I removed it since the article is already over-crowded with images. Klubbit (talk) 20:14, 17 April 2010 (UTC)

Atmospheric effects
[addendum] "I can't find a volume/tonnage spreadsheet of volcanic ash fall and particulate atmosphere injection over world history, here or elsewhere obvious. Current terrestrial volcanism is several multiples of recent (or historical) awareness. How much closer are we getting (significantly or otherwise) to global nuclear winter? Again, neither easy numbers nor relevant analysis available.2601:601:E04:AE0:6408:6198:2789:8813 (talk) 19:07, 23 December 2021 (UTC)"

I think I might have edit this slightly. I am new to Wiki, so please bear with me. The section on atmospheric effects is not right - the NASA web page clearly states that sulphate, not ash, is reponsible for post-eruptive global cooling. Imatt.watson (talk) 15:59, 19 June 2009 (UTC)


 * Hi, and welcome to Wiki. I took a look at the NASA source, and you're pretty much right - though it says yes to sulfates and nothing about ash, as opposed to specifically saying no to ash. Feel free to change for the time being, though I would think that volcanic ash must play a role in intercepting / reflecting incoming solar radiation... I'll look for a reference. Awickert (talk) 16:38, 19 June 2009 (UTC)

Well, global dimming from volcanic ashes might have an effect for, let's say, weeks. Sulfur dioxide gets oxidized to sulfate, let's say, 3 weeks, sequestrates water and causes global dimming for let's say 3 years. --Chris.urs-o (talk) 06:11, 19 April 2010 (UTC)

conducts electricity
"volcanic ash ...conducts electricity, especially when it is wet". Does the ash conduct when dry? Even when wet does it conduct? This looks like a reference required. Mtpaley (talk) 22:58, 16 April 2010 (UTC)

Aviation
On TV a Swiss International Air Lines chief pilot, if I remember it right, listed four main consequences: but I have no verifiable reference, sorry. --Chris.urs-o (talk) 09:07, 17 April 2010 (UTC)
 * Sandblasting effect
 * Melting of the ash and clogging and out-of-balance of the turbines (cut out)
 * Clogging of the sensors, including air speed
 * The static charged particles make it impossible to use the radio communication.


 * Quote: "Simple lack of oxygen is given as a probable cause of engine failure." I think this claim is doubtfull. KLM Flight 867 and BA Flight 9 did not have this problem, as I understand. --Chris.urs-o (talk) 15:51, 20 April 2010 (UTC)
 * It's given by actual, reliable Sources. No Doubt this has to be mentioned! --Itu (talk) 13:30, 21 April 2010 (UTC)

If pitot tubes get blocked, it will certainly have an impact on the altimeter as well as on the airspeed indicator. Both these instruments use pitot tubes. See Birgenair Flight 301 (Though the ASI's pitot tube is more likely to be impacted since its opening faces the airstream.) - 207.96.181.42 (talk) 13:54, 19 April 2010 (UTC)


 * Does anyone think about direct human impacts? I remember having heared that volcanic products can consist of hazardous substances any now and then. Fatalities at lakes with sulfur oxides or carbon oxides got reported in past times. If humans are going on an airplane it can impact them as well even if the air is going trough some filters and a compressor before its useable. this might even be a danger if pilots and all others were using oxygen masks for improving their breath functionality. (humans can absorb any sort of substance via their skin, having extra oxygen does not mean you dont get any other air intake to your lungs). in general a paragraph on possbile human impacts is missing. --13:43, 18 April 2010 (UTC) —Preceding unsigned comment added by Alexander.stohr (talk • contribs)

Carbon Dioxide, Hydrofluoric acid, Sulfur-dioxide are dangerous; but they are not volcanic ashes. We are talking from consequences at 500 km away from the source. Locally, the ash is poison for Ruminants. --Chris.urs-o (talk) 06:14, 19 April 2010 (UTC)

Citation needed
I think this is an overkill sometimes. We can't say one and one is two and get a citation.
 * Quote: "and coat the plane so much as to add significant weight and change balance"
 * Edit summary quote: "never heard that ..."
 * Comment: if you coat a plane, you change its weight and balance. But sure, I do not know if it is relevant here before all fuel is burnt.
 * "Volcanic ash damages machinery." so "Propellor aircraft are also endangered" too.
 * Volcanic ash can "fuse onto the blades and other parts of the turbine, it can erode and destroy parts." And so it can drive a machinery rotating at high angular velocity out-of-balance. Again if the mass changes, it changes the balance too.
 * Its common sense. After primary, secondary and college you must know that. --Chris.urs-o (talk) 15:01, 20 April 2010 (UTC)

Edit request from Ltryan, 20 April 2010
Ash is not ejected to 30,000ft as suggested by Dr. Dougal Jerram. As an earth scientist at a respected university he knows this and should not be peddling this over simplified description to Joe public. Ash rises buoyantly due to its temperature when ejected. Very simple proof of this is to view a pyroclastic eruption running down the side of a volcano and the ash cloud "taking off" to 30,000ft from it. Often as far as the base of the volcano, where it is impossible that it is ejected.

Ltryan (talk) 16:17, 20 April 2010 (UTC)
 * If you have a primary source, you can either make the change yourself and provide the proper inline reference, or put a link to the primary source here so someone else can make your requested change. Thegreatdr (talk) 18:49, 20 April 2010 (UTC)


 * Do not undestand this. The quote does not talk about 30,000 ft. --Chris.urs-o (talk) 19:27, 20 April 2010 (UTC)

Edit request from Geo-editing, 20 April 2010
The second paragraph about the effect of volcanic ash needs to be deleted, as it does not conform to the current state of understanding of volcanic effects.

(Briefly, volcanic ash only has a short residence time in the stratosphere, and it is volatile gases, specifically SO2 which have multi-year residence times and cause the climatic effects referenced to ash particles in this paragraph. Given the current interest in volcanic ash, this paragraph should be deleted, and maybe reference to the wikipedia article on volcanoes http://en.wikipedia.org/wiki/Volcano third paragraph of volcanic effects, which gets the issue correct, inserted for now.  I also put my concern down on the talk page, but thought I'd double up here since this is very topical at the moment and the wiki page is probably getting a lot of hits and propagating a scientific 'urban myth'.  Thanks)

Geo-editing (talk) 18:50, 20 April 2010 (UTC)


 * Agree. Deleted the cooling through ash (citation needed really). --Chris.urs-o (talk) 19:39, 20 April 2010 (UTC)

Thanks Chris- I added some details about the residence time of ash in the troposphere and stratosphere to a paragraph on my wiki page (hope i did it correctly) with a reference (also added a brief sentence about SO2, because people who come to this page thinking that volcanic ash causes climate effects would be confused not to find it here. I also edited the bishops ring wiki page to reflect that it is also SO2 derivatives that cause that effect, so it should be removed from the volcanic ash page as well.  Geo-editing (talk) 20:08, 20 April 2010 (UTC)

Do u have a ref that bishop ring is sulfur dioxide? I think this can do any aerosol. It is too late now, I have to think about your requests. --Chris.urs-o (talk) 20:20, 20 April 2010 (UTC)

I put 2 referencse on the Bishop's ring page, it's not SO2, it's an aerosol derived from SO2, probably H2SO4, but I'm not a chemist, so I equivocated and just called it a sulfur compound aerosol. Either way, all the references I found implicate SO2 derived aerosols, NOT volcanic ash (ie. tephra). It would probably be valid to just say H2SO4. —Preceding unsigned comment added by Geo-editing (talk • contribs) 20:43, 20 April 2010 (UTC)

Good articles from the horses mouth.
This hasn't been used in the article - http://www.boeing.com/commercial/aeromagazine/aero_09/volcanic_textonly.html

Also from the UKs CAA - ''"The major barrier to resuming flight has been understanding tolerance levels of aircraft to ash. Manufacturers have now agreed increased tolerance levels in low ash density areas."

''In addition, the CAA’s Revised Airspace Guidance requires airlines to:

''· conduct their own risk assessment and develop operational procedures to address any remaining risks;

''· put in place an intensive maintenance ash damage inspection before and after each flight; and

''· report any ash related incidents to a reporting scheme run by the CAA. '' http://www.caa.co.uk/application.aspx?catid=14&pagetype=65&appid=7&mode=detail&nid=1862

History of ash clouds
1 ash cloud in 2010 in april went for 7 days

Re write of entire page
Within the next few weeks I plan to re write the entire volcanic ash page to provide more details on ash formation and its physical and chemical properties. This re write will also include a large discussion on other impacts of ash, other than on aircraft. This will bring the article up to date with current scientific understanding. Grantw13 (talk) 19:03, 27 March 2012 (UTC)


 * I suggest this photo: http://volcanoes.usgs.gov/Imgs/Jpg/Tephra/30410914-076_large.jpg — Preceding unsigned comment added by 71.171.106.16 (talk) 22:21, 24 February 2013 (UTC)


 * This image may be useful for adding a human factor to the ash article. — Crisco 1492 (talk) 07:18, 16 February 2014 (UTC)

Size graph?
The graph in the section "Grain size" is hard to interpret, since the measurement "phi" is not explained, and the units are not labelled. Geoffrey.landis (talk) 19:41, 4 March 2014 (UTC)

Is there any warning sign of volcanic ashfall, and is it?
ASAP pls. 124.105.207.240 (talk) 04:08, 1 January 2022 (UTC)