User:Surbhi ghadia/sandbox

Introduction:
- Accretionary thrust should be simplified or explained

- "Methane is seeping into the ocean at this site..." as it transitions into gaseous phase? You should provide some brief description of why the methane does not remain trapped, since your previous sentence would suggest that it does.

- When it was discovered/became important would be a good fact to place in the intro

Significance:
- Don't forget to add in citation

- I would phrase your sentence about fossil fuels differently so it does not come accross as an interpretation made by you. For instance, "One motivator for research at Hydrate Ridge is uncovering the potential for methane seeps as a fossil fuel source."

History of Observations:
- "with the discovery of (esp. cool) venting sites..." I think the average reader won't understand what you mean, so I recommend being explicit about Hydrate Ridge's low-temperature vents

- "gas fluxes at Hydrate Ridge are affected more by diurnal patterns than by seasonal ones" If you have the information, I would include an additional sentence here explaining why diurnal/seasonal patterns are/were thought to be important (i.e. what forcings are related to these cycles).

Subsurface Structure:
- I don't think anything is gained from the use of acronyms (OBH,OBS,ODP)

Methane Venting:
- Acronyms

- Sentences on free gas zone fall flat. How does this zone influence output? Why is this zone interesting/important (i.e. does its influence vary from site to site)?

OOI Cabled Array:
- Add a brief sentence describing that the OOI cabled observatory collects data/delivers it to shore in real time. You don't need to go into detail, but just enough so that the readers understand why this is useful at Hydrate Ridge.

Hydrate Ridge Article Draft (Edited)


Hydrate Ridge is an accretionary thrust clathrate hydrate formation, which means it is made of sediment scraped off of subducting oceanic plate. It is approx. 200 m (700 ft) high, and located 100 km (62 mi) offshore of Oregon. At hydrate formations, methane is trapped in crystallized water structures. Such methane transforms into gaseous phase and seeps slowly into the ocean at this site, which has been a popular location of study since its discovery in 1986. Hydrate Ridge supports a methane-driven benthic community.

Reminder to view the actual Hydrate Ridge page for further edits (mostly grammar and syntax).

Significance
Hydrate Ridge and other hydrate formations store methane for extended periods of time. This methane can be released back into the ocean as a result of underwater seismic activity or other sudden movements. Methane is a potent greenhouse gas, and the study of hydrate formations can lead to information about their influences on the global carbon cycle and carbon sequestration.

Because it is one of the most easily accessible hydrate formations in the ocean, and because the global effects of oceanic methane release are still poorly understood, Hydrate Ridge has received significant scientific attention since its discovery. The presence of venting sites and a benthic community there, along with the ridge's association with the Cascadia Subduction Zone (as an accretionary formation), has made it a location at which hydrate and subduction zone characteristics are widely studied. It is a popular site for conducting research related to gas hydrate deposits.

Another motivation to study Hydrate Ridge has been to uncover methane seeps as a potential source of fossil fuels. Research there may reveal the economical value of such structures.

History of Observations
The importance of Hydrate Ridge was recognized in 1986, with the discovery of low-temperature venting sites and a methane-driven biological community there. Since then, information has been collected on bubble emission frequencies, plume heights, etc. at the ridge, particularly via use of remotely operated underwater vehicles, to further our scientific understanding of it.

A 2001 bubble plume study suggested that the free gas zone (see "Methane Venting") under surface sediments at Hydrate Ridge is thick. If this is the case, and if other active hydrate formations share this characteristic, more methane may be released (and influence climate change) than was anticipated prior to the study, according to researchers.

A 2016 study indicated that gas fluxes at Hydrate Ridge are affected more by diurnal patterns than by seasonal ones.

Subsurface Structure
In 1996, the Ocean Drilling Program deployed ocean bottom hydrophones and ocean bottom seismometers around Hydrate Ridge. The data from these tools was analyzed in a 2001 study, in which the velocities of refracted seismic waves helped scientists estimate the subsurface contents of the site (e.g. free gas features).

Methane Venting
Methane is being released at Hydrate Ridge, particularly through cold seeps. The Southern Hydrate Ridge (SHR) is believed to be an especially active part of the formation. However, a 2016 study has asserted that the Summit of the SHR is not the sole structure involved in subseafloor gas and fluid transport. Smaller fluxes occur elsewhere.

The free gas zone is a zone of freed methane in a hydrate formation, beneath the hydrate stability zone. It can influence the rate of methane output at a ridge or ridge region. A large free gas zone makes more methane available to be released into the open ocean, and, thus, can likely be more influential on climate change than a smaller one.

Biology
Hydrate Ridge houses several species of methane-utilizing benthic organisms, including Calyptogena clams and microbial mats. A 2001 study proposed that the microbial mats at this site correlate to heavy outflow at cold seeps. It claimed, too, that Calyptogena function with the help of sulfide-oxidizing bacteria (sulfide is a product of methane oxidation).

The aforesaid aligns with a 1986 study, which stated that several large organisms at Hydrate Ridge work symbiotically with microorganisms to produce energy from methane.

Ocean Observatories Initiative Cabled Array
Part of the Ocean Observatories Initiative Cabled Array has been assembled on the Southern Hydrate Ridge. The cabled array collects and sends data on shore in real time. As a result, it enables scientists to make more, continuous observations of seasonal effects on vent activity, and of links between changes in methane flux and biochemical cycles at this specific location.

Hydrate Ridge Article Draft
Note: See 'Hydrate Ridge Article Improvements' for some notes I took during Week 5 as well.

(Edited) Lead Paragraph
Hydrate Ridge is an accretionary thrust clathrate hydrate formation {appx. 200 m (700 ft) high}, located 100 km (62 mi) offshore of Oregon State. Ridges like this one store more than 50% of the Earth's emplaced carbon reserves, and release large amounts of methane in cold seeps.

Because it is one of the most easily accessible such formations in the ocean, and because the global effects of oceanic methane release are still poorly understood, Hydrate Ridge has received significant scientific attention since its discovery.

Ridge Traits
Hydrate formations, such as Hydrate Ridge, store methane for extended periods of time. This methane can be released back into the ocean as a result of underwater seismic activity or other sudden movements. Methane is a potent greenhouse gas, and the study of hydrate formations can lead to information about their influences on the global carbon cycle and carbon sequestration.[citation needed]

The importance of Hydrate Ridge was recognized in 1986, with the discovery of (esp. cool) venting sites and a methane-driven animal community there. The Southern Hydrate Ridge (SHR) is particularly active. These discoveries, along with its inherent association with the Cascadia Subduction Zone (as an accretionary formation), has since made the ridge a location at which hydrate and subduction zone characteristics are widely studied. It is a popular site for conducting research regarding gas hydrate deposits, in general.

Hydrate Ridge houses several species of methane-utilizing benthic organisms, including Calyptogena clams and microbial mats.

Key Findings
A 2016 study indicated that gas fluxes at Hydrate Ridge are affected more by diurnal patterns than by seasonal ones. It also asserted that the Summit of the SHR is not the sole structure participating in subseafloor gas and fluid transport. A 2001 bubble plume study suggested that the free gas zone under surface sediments at the ridge is thick. If such is the case, for this formation and for others, more methane may be released (and influence climate change) than was anticipated prior to the study, according to researchers.

Some of the projects/organizations commonly associated with Hydrate Ridge research are:
 * The Ocean Drilling Program (ODP)
 * Ocean Observatories Initiative (OOI)

Research Methods
Remotely operated underwater vehicles (or ROVs) are at times used to collect information, such as data on bubble emission frequencies and plume heights, at Hydrate Ridge. Additionally, a site of the OOI Cabled Array is located at the southern part of the ridge. The cabled array enables the scientific community to make more, continuous observations of seasonal effects on vent activity, and of links between changes in methane flux and biochemical cycles there. Seismic velocities are examined as well.

Hydrate Ridge Article Improvements
As of now, the Hydrate Ridge article is extremely short. However, it displays a short list of somewhat credible sources.

Ideas for expansion: Possible sources to incorporate:
 * No information on the origins of the ridge is yet given in the article. When, how, why do scientists propose it formed?
 * The article claims that "Hydrate Ridge has received significant scientific attention since its discovery". I wish to mention and explain examples of the type of scientific attention it has gotten. What has Hydrate Ridge indicated to the scientific community about other similar structures on the Earth? How has this information been further studied?
 * Which groups most commonly study the ridge? What methods have been/are currently used to conduct studies?
 * An article from the New York Times is listed as a source. Does the text associated with it show signs of bias?
 * Many of the articles explore the southern part of the ridge, explicitly. What is so important about the southern Hydrate Ridge?
 * Bangs, Nathan L.; Dugan, Brandon; and Daigle, Hugh. "Transient Hydraulic Fracturing and Gas Release in Methane Hydrate Settings: A Case Study from Southern Hydrate Ridge." Geochemistry, Geophysics, Geosystems G³. 12.12 (2011): N/A. Web.
 * Chen, Duofu; Cathles, Lawrence M.; and Cao, Yuncheng. "A Kinetic Model for the Methane Hydrate Precipitated from Venting Gas at Cold Seep Sites at Hydrate Ridge, Cascadia Margin, Oregon." Journal of Geophysical Research. 118.9 (2013): 4669-681. Web.
 * Constable, S.; Trehu, A. M.; and Weitemeyer, K. A. "A Marine Electromagnetic Survey to Detect Gas Hydrate at Hydrate Ridge, Oregon." Geophysical Journal International. 187.1 (2011): 45-62. Web.
 * Denny, Alden R.; Solomon, Evan A.; Kelley, Deborah S.; and Philip, Brendan T. "Time-Series Measurements of Bubble Plume Variability and Water Column Methane Distribution above Southern Hydrate Ridge, Oregon." Geochemistry, Geophysics, Geosystems G³. 17.3 (2016): 1182-196. Web.
 * Haley, Brian A.; Torres, Marta E.; Klinkhammer, Gary P.; Bohrmann, Gerhard; Himmler, Tobias; and Peckmann, Jörn. "Rare Earth Element Geochemistry in Cold-Seep Pore Waters of Hydrate Ridge, Northeast Pacific Ocean." Geo-Marine Letters. 33.5 (2013): 369-79. Web.
 * Trehu, Anne M.; Pierce, Stephen D.; Paull, Charles K.; Caress, David W.; and Kannberg, Peter K. "Temporal Variation of Methane Flares in the Ocean above Hydrate Ridge, Oregon." Earth and Planetary Science Letters. 368 (2013): 33-42. Web.

''It looks like you're off to a great start on your sources. These are all fairly recent publications, so they may take some background information on Hydrate Ridge for granted. I recommend looking at prior publications by these same authors or listed in the references of the above papers if you have trouble.'' Erik 03:54, 24 April 2017 (UTC)

''This is a great start. Hydrate Ridge is a site on the OOI cabled array. the have broken link already there incorrectly attributed to Washington University but working ones are http://ooicruises.ocean.washington.edu/story/Hydrate+Ridge and http://oceanobservatories.org/array/cabled-continental-margin/ and http://www.interactiveoceans.washington.edu/story/Methane_Hydrates_Southern_Hydrate_Ridge Also this might be a great article since it seems to be a historical perspective on studies at hydrate ridge http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/55610/SuessErwinCEOASLegacyOfHydrateRidge.pdf;jsessionid=ED158DE3FE8A90ED180A4AF1E39DBFC6?sequence=3'' William Wilcock (talk) 05:55, 24 April 2017 (UTC)

Notes on Week 5:
 * I am currently looking through the articles suggested above for historical information on Hydrate Ridge. I would like to use this information to better understand the sources I listed and to answer some of the questions I have posed. All of the sources in the current article are from 2012, and hence, are also not focused on historical information.
 * I am also searching for additional neutral sources that could provide background information on Hydrate Ridge. Here are some of my findings:
 * Trehu, Anne M.; and Flueh, Ernst R. "Estimating the Thickness of the Free Gas Zone beneath Hydrate Ridge, Oregon Continental Margin, from Seismic Velocities and Attenuation." Journal of Geophysical Research: Solid Earth. 106.B2 (2001): 2035-045. Web.
 * Tryon, Michael D; and Brown, Kevin M. "Complex Flow Patterns through Hydrate Ridge and Their Impact on Seep Biota." Geophysical Research Letters. 28.14 (2001): 2863-866. Web.
 * I plan to add more physical descriptions of the ridge, including details about ridge topography (for which an image is currently given, but no description).
 * I plan to add details on how methane is released from Hydrate Ridge (hopefully, I become able enough to understand this through my reading).
 * I have to remember not to go too far into this, because I do not want to distract from the article.
 * If I find images in the sources that can enhance the article, I will try to incorporate them.
 * I plan on creating sections for "Key Traits" and important studies related to the ridge, amongst others.

==Week 3 assignment++

''For Week 3, you added a good new point to the Cabled Observatories page. I edited it slightly to improve clarity. Look at the page history'' William Wilcock (talk) 01:18, 17 April 2017 (UTC)

Critiques of Articles
''This is a very detailed critique. Nice job. Also a good addition to the talk page of Divergent boundary'' William Wilcock (talk) 01:18, 17 April 2017 (UTC)

Plate Tectonics
'' Is each fact referenced with an appropriate, reliable reference? '' Most of the facts that appear within the article are appropriately referenced (especially in relation to quantitative information). However, some claims are made that, regardless of if the editor is 100% certain of them, could be improved if supported by a source. An example of one such claim is: "However, [Wegener's] ideas were not taken seriously by many geologists, who pointed out that there was no apparent mechanism for continental drift. Specifically, they did not see how continental rock could plow through the much denser rock that makes up oceanic crust". Evidence for this statement can likely be found in published form.

NOTE: A 'template message', located above the "Driving forces related to Earth rotation" section, indicates that more reliable references need to be added there.

The noted references seem adequately reliable. In fact, the References section is split into "Notes" plus two more categories, "Cited books" and "Cited articles". Within these categories, there appear citations for generally independent sources (from printed books, scholarly articles, and government websites), which do not display heavily biased titles. Also, a wide variety of sources is listed overall; the information has been accumulated from several places, arguably over a long time, and (hopefully) with limited carelessness.

''Is everything in the article relevant to the article topic? Is there anything that distracted you?'' The editors of the page, for the most part, keep things relevant to the main topic. When a complicated (yet not completely relevant) topic is mentioned, the reader is urged to learn more about it elsewhere: "Modern theories that continue building on the older mantle doming concepts and see plate movements as a secondary phenomena are beyond the scope of this page and are discussed elsewhere (for example on the plume tectonics page)". Nonetheless, the "Other celestial bodies (planets, moons)" section is somewhat distracting, because it diverges from the subject of the Plate Tectonics theory, especially in connection to the Earth. Slight mentions of observations of plate tectonics on other bodies do not hurt, but the extended focus on this section may be unnecessary.

''Is the article neutral? Are there any claims, or frames, that appear heavily biased towards a particular position?'' The article is considerably neutral. When a concept is being, or has been debated, such is clearly stated: "Lately, the convection theory has been much debated as modern techniques based on 3D seismic tomography still fail to recognize these predicted large scale convection cells". Some claims that indicate an attitude are made (e.g. "Ironically, these systematic relations..."), as are some that hint at assumption (e.g. "It has generally been accepted that tectonic plates are able to move because...", "Forces related to gravity are usually invoked as secondary phenomena..."); however, these are not prevalent or biased enough to shift one's attention from the topic at hand (plus, the assumptions seem to inferred from accumulated information about the topic).

''Where does the information come from? Are these neutral sources?'' (You can also see Question 1.) The cited sources are majorly from books, atlases, articles in science magazines and in scientific journals, government websites (e.g. NASA.gov), etc. Mostly (assuming from their origins and titles), these should be neutral sources (i.e. they do not support a specific bias, their purpose is not to market a product, they demonstrate independent research conducted for scientific purposes, they are secondary sources, etc.).

Some sources under the "Notes" section are interactive websites (e.g. "Plate Tectonics: Plate Boundaries". platetectonics.com. Retrieved 12 June 2010.).

Are there sub-topics that are over-represented, underrepresented or missing? Though I, personally, feel the sections describing the "Development of the theory" (e.g. "Magnetic striping") are too lengthy, and thus, moderately confusing, I acknowledge their value in the article. They are topics that need to be well-understood for one to comprehend the history and significance of the Plate Tectonics theory. Ultimately, they are not necessarily over-represented. The "Plate reconstruction" section, on the other hand, can be expanded. Although this is not the main page for plate reconstruction, it could be helpful for a reader to know more about the work scientists currently use the Plate Tectonics theory for (e.g. "Past plate motions"). Further representation of this section can outline the important implications of what is aforementioned on the page (address the 'so what?').

'' Do the illustrations and images add to the article, and are there illustrations/images that could be usefully added? '' The illustrations within the article are appropriately placed, and help to visualize what is being explained in the text. In particular, the illustrations of the three main plate boundaries (i.e. transform, divergent, and convergent) are excellent visual aids. The article could be further improved with the addition of an illustration displaying the generation of new oceanic crust at a mid-ocean ridge, and the corresponding subduction of old oceanic crust at a subduction zone, under "Mid-oceanic ridge spreading and convection" (because the importance of the "Great Global Rift" is expressed). Illustrations depicting mantle convection (e.g. "material", "mineral", and "thermal" stratification shown) can also be added, under "Driving forces related to mantle dynamics".

''Check a few citations. Do the links work? Is there any close paraphrasing or plagiarism in the article?''

(Citation #1): Mallard, Claire; Coltice, Nicolas; Seton, Maria; Müller, R. Dietmar; Tackley, Paul J. (2016). "Subduction controls the distribution and fragmentation of Earth's tectonic plates". Nature. 535 (7610): 140–143. Bibcode:2016Natur.535..140M. doi:10.1038/nature17992. ISSN 0028-0836. (Citation #2): Grove, Timothy L.; Till, Christy B.; Krawczynski, Michael J. (8 March 2012). "The Role of H2O in Subduction Zone Magmatism". Annual Review of Earth and Planetary Sciences. 40 (40): 413–439. Bibcode:2012AREPS..40..413G. doi:10.1146/annurev-earth-042711-105310. Retrieved 14 January 2016. ''Is any information out of date? Is anything missing that could be added?'' The article was last updated 7 April 2017, and seems to be reasonably up-to-date. Where applicable, recent studies are mentioned,and their results are compared to older ones: "In a more recent 2006 study, scientists reviewed and advocated these earlier proposed ideas".
 * The link works!
 * In Plate Tectonics article: "Recent research, based on three-dimensional computer modeling, suggests that plate geometry is governed by a feedback between mantle convection patterns and the strength of the lithosphere ."
 * In original work: "Here, we demonstrate that the plate layout of the Earth is produced by a dynamic feedback between mantle convection and the strength of the lithosphere ."
 * The second half of the sentence in the Plate Tectonics article is very close to the original phrasing.
 * The link works!
 * In Plate Tectonics article: "The addition of water lowers the melting point of the mantle material above the subducting slab, causing it to melt. The magma that results typically leads to volcanism."
 * In original work: "Small amounts of H 2 O given off by the subducting slab lower the melting point of peridotite to between 800 and 820°C at 3 GPa..."
 * The Plate Tectonics article has phrased this sentence well, and has excluded information not vital to the overall page.

I do not notice any major missing topics from the article, and I doubt I am educated enough on this theory to notice small ones.

'' Check the "talk" page - what conversation is the Wikipedia community having behind the scenes about how to represent these topics? '' In certain places on the "talk" page, editors are questioning the validity of specific numbers ("error in estimate of thickness of oceanic lithosphere?") or asking for clarification on definitions/names ("who is David Pratt?"). The "talk" page not only enables people to debate with, correct, or update one another, it is also a place where editors can gain more knowledge about the topic (often so that the article will be more accurate). One particular debate that interests me on this page is that titled "NPOV", in which Revent suggested to include "opposing views" to Plate Tectonics, such as "Flood Geology". The debate focuses on if or not "religious pseudoscience" should be incorporated into an article, because "it is a set of opinions held by many" (Revent).

'' What is the article rated? '' C-Class (quality scale); no rating (importance scale).

'' How does the way these subjects are discussed on Wikipedia differ from how they have been discussed in your prior Earth Science classes? '' The article goes into much more detail, and accredits more scientists, than I am used to from my prior Earth Science classes. Even in Geology courses, I have not been exposed to this much information on the Plate Tectonics theory, likely because too much time on one topic can confuse a student when it comes to the general picture. The article takes dozens of sources into account, and acknowledges more notions as 'currently debated' than I am accustomed to. This could mean the article is a better resource for me to learn about this topic than a course; but, it likely means it is a more often altered, more variable, and more confusing place to attain knowledge from, considering I also take what I learn in school with a grain of salt.

Divergent Boundary
Is each fact referenced with an appropriate, reliable reference? NO! Only one citation is made within the entire article. The following could have definitely been cited: ''Is everything in the article relevant to the article topic? Is there anything that distracted you? What is written seems relevant, yet it is not enough'' for me to contemplate being distracted. I finished reading the article before my mind could take any tangents. However, the odd grammar does make it easy to get confused and need to pause. I had to reread the following sentence several times to comprehend it correctly: "If one views the sea floor between the fracture zones as conveyor belts carrying the ridge on each side of the rift away from the spreading center the action becomes clear". There is also a longer-than-necessary portion (compared to how much is written overall) on transform faults.
 * "Over millions of years, tectonic plates may move many hundreds of kilometers away from both sides of a divergent plate boundary." Do we assume this?
 * "The origin of new divergent boundaries at triple junctions is sometimes thought to be associated with the phenomenon known as hotspots." Thought by whom, originally?
 * "The hot spot which may have initiated the Mid-Atlantic Ridge system currently underlies Iceland which is widening at a rate of a few centimeters per year ." How do we know?!
 * "Scientists had been studying polar reversals and the link was made by Lawrence W. Morley, Frederick John Vine and Drummond Hoyle Matthews in the Morley–Vine–Matthews hypothesis." Why not cite a work that can confirm this? Or, better yet, the works of these people?!
 * "Crest depths of the old ridges, parallel to the current spreading center, will be older and deeper... (from thermal contraction and subsidence)."[citation needed]

''Is the article neutral? Are there any claims, or frames, that appear heavily biased towards a particular position?'' Most of the article appears to be neutral, though, again, there is not much text to assess. As is indicated by the sentence, "It is at mid-ocean ridges that one of the key pieces of evidence forcing acceptance of the seafloor spreading hypothesis was found", the editor may be slightly unsatisfied by (or in agreement with?) the seafloor spreading hypothesis (which is not linked to its own Wikipedia article, and should be). But, the editor provides no other examples of what hypotheses and/or claims the seafloor spreading hypothesis was formerly (or is currently) challenged by, after this statement.

''Where does the information come from? Are these neutral sources?'' The jargon of the sourc e referenced in the article is not completely neutral. Still, the authors of the paper show excitement about research results, rather than bias towards a hypothesis prior to study. For example, they write "One of the most exciting results from the last 5 years is the verification of deep penetration of former oceanic lithosphere into the lower mantle (1–3)...Thus, strictly layered mantle convection can now be ruled out with good confidence ". Additionally, the content of this source was presented at the Japanese-American Frontiers of Science symposium in 1999, and should, therefore, be quite scientifically reliable.

Are there sub-topics that are over-represented, underrepresented or missing? There are not many sub-topics listed to be over-/underrepresented ("Description" for textual).

The following are examples of missing sub-topics: Do the illustrations and images add to the article, and are there illustrations/images that could be usefully added? Though the images and illustrations in the article are helpful, they are far from sufficient (in terms of quantity, at least). The text states: "A sea floor map will show a rather strange pattern of blocky structures that are separated by linear features perpendicular to the ridge axis"; instead of forcing the reader to visualize this image independently, a (bathymetrical) map of the seafloor could be included. The image provided of the Álfagjá Rift Valley is a nice visual aid, but the satellite image of a MOR (e.g. the East Pacific Rise) might be more useful to have, in correspondence with the text. It would also probably be a good idea to add an illustration of a divergent boundary with labels (especially for the Earth's layers) to accompany the first illustration on the page.
 * Mantle convection (mentioned, but not given enough detail or importance**) - mentioned only in the introduction, not elsewhere. Why is it important for divergent boundaries?
 * Mid-ocean ridges (**) - the article would be easier to follow if most of the information pertaining to MORs appeared under one sup-topic.
 * Rift valleys (**) - can be elaborated on much more; hardly any description is provided. How do they form? What kinds of geological features do they create?
 * Seafloor spreading hypothesis (**) - more information on the relationship between the age of oceanic crust and its distance from a divergent boundary should be included.
 * Triple junctions (**) - What are they? Why are they, and hot-spots, important enough to mention in this particular article?
 * Fast/slow spreading centers - Why do different divergent boundaries differ in the speed at which they produce new crust?

''Check a few citations. Do the links work? Is there any close paraphrasing or plagiarism in the article?''

(Only Citation): Toshiro Tanimoto, Thorne Lay (November 7, 2000). "Mantle dynamics and seismic tomography". ''Proc. Natl. Acad. Sci. U.S.A''. 97 (23): 12409–10. Bibcode:2000PNAS...9712409T. doi:10.1073/pnas.210382197. PMC 34063. PMID 11035784. ''Is any information out of date? Is anything missing that could be added?'' The information in the article is vaguely referenced and dated; it is difficult to decipher whether the claims made within it are still valid (or, for that matter, to differentiate said claims from one another). Most of what is written should be current (or, it seems that way to me, according to what I have learned in classes thus far). However, the only reference used was presented in 1999, so information/evidence from more current sources likely needs to be added.
 * The link works!
 * In Divergent Boundary article: "Current research indicates that complex convection within the Earth's mantle allows material to rise to the base of the lithosphere beneath each divergent plate boundary."
 * In original work: No representative sentence can be found; the aforementioned is an imprecise summary of the source.

'Anything missing that could be added' includes clarifications and additions to several 'lazy' sentences. For example, the sentence "These are the fracture zones, many bearing names, that are a major source of submarine earthquakes" should be expanded to list some of those names. And, "Crest depths of the old ridges, parallel to the current spreading center, will be older and deeper...", a sentence which is never formally concluded in the article, should be extended into a referenced, coherent piece of information.

Check the "talk" page - what conversation is the Wikipedia community having behind the scenes about how to represent these topics? Some of the conversations on the "talk" page are not very serious. Though a few of them are about constructive changes made to the article (e.g. "Change in lede") or about adding new sources to it (e.g. "New article for Rift volcano"), there are also conversations such as that titled "Not fun", in which an editor are claims that "I got to do a project for school. Thats the only reason I'm here". The constructive conversations indicate little-to-no communication between editors, while the rant-like conversations actually display more interaction (unity in complaints, is it?).

What is the article rated? Start-Class (quality scale); Mid-importance (importance scale).

How does the way these subjects are discussed on Wikipedia differ from how they have been discussed in your prior Earth Science classes? The way in which divergent boundaries are described in the article is rather dreadful, in my opinion. Compared to what I have learned of them in classes, the article provides little detail, little explanation behind why certain phenomenon occur, few clearly understandable statements, few visual aids, and few resources to look into. If I were to choose between using the Wikipedia article on divergent boundaries and my own related in-class notes from the past year to write a paper, I would use my notes, regardless of how unprofessional it would be.

Note: I have inserted my notes about what I learned (or wanted to learn, but did not encounter) from these articles into parts of my answers above!

Bold Tutorial
"Being bold is important on Wikipedia."