User:Cadotc/sandbox

Good to see you adding two citations in week 3 for extra credit. Both are good choices William Wilcock (talk) 23:03, 16 April 2017 (UTC)

These are really detailed notes and you do a good job touching on all the questions in the assignment. I also see that your suggestion for more illustrations on the Plate Tectonics talk page has led to a change in the page. William Wilcock (talk) 05:06, 10 April 2017 (UTC)

plate tectonics article: Begins with broad overview of number of plates, how they are divided over the Earth, and how the movement of plates is driven. After general introduction to topic, has a chart of contents with the other major subtopics that will be covered in the article. Describes the main principles that drive tectonic plate motion like how they move by riding over a viscous asthenosphere. Then goes into the general categories of plate movements (i.e. convergent, divergent, transform). Next several subtopics are the major forces that act in plate tectonic movement like gravity and dynamics due to a rotating earth. Then the history of the principle is described from its introduction in 1915 by Wegener, and it is described what evidence Wegener used to back up his theory. Tracks development of theory and opposition to the theory as well as new findings that gave more validation to his theory. Also goes into whether tectonic plates exist on other planets, which was interesting. Questions and critique: language concise, not too flowery. could use more links on some terms like conveyor belt principle. Every time there are specific facts mentioned, they are followed by citations. Does not appear to plagiarize anything. Organization: each subtopic broken into its own section. Allows for better presentation of data. Presents many different sources and theories to provide well rounded, unbiased information. could use a figure that shows the layers of the earth and their composition. The article stayed neutral and did not take any sides but merely expressed a variety of theories, ideas, and facts. The facts appear to come from reliable sources like from academia. could have illustration that shows other indications of plate boundaries around the world like the age of seafloor (younger by sea ridges) or areas of earthquakes and depths of earthquakes. I feel like all the topics were represented well and were relevant to the plate tectonics however I think that the plate tectonics on other planets could have been just a link to its own article because I feel like that should be its own thing. Some things mentioned on the article's talk page is that it could be updated to reference new information from recent papers. There was also someone saying that there should be an acknowledgement in the article to the opposing "Flood" biblical theory. Other people were nitpicking on the rotational influences on plate tectonics and improvements that could be made to that section. In comparison to discussing this topic in classes I have taken, a lot more details was discussed here and the portion about tectonic plates on other celestial bodies has never been broached in my classes.

Convergent boundary article: Begins broadly with definition of convergent boundary and the different kinds of convergent boundaries (continental/ continental or continental/ oceanic crust, etc) Discusses why at different convergent boundaries one thing will happen versus another like at oceanic/ continental crustal collisions, oceanic crust dives under because of higher density. Uses numbers to quantify the difference in densities of the two. Gives examples of results of different convergent boundaries (i.e. trench or island arc) Talks about plate boundaries- could use figure here of map of earth with plate boundaries. Not enough illustrations. Could have figures showing composition of the earth, or illustrations of different examples of convergent boundary formations like island arcs and etc. Questions: The facts are followed by citations for a reference but there probably could be more citations and there is only a single source. The first citation doesn't occur until about three paragraphs in, but the beginning information is so general that it can probably be classified as common knowledge. The links are functional and will take the user to other Wikipedia articles to learn more on that topic. Information is pretty cut and dry and neutral; no sides taken. Sources neutral too- come from just one source which is academic- some geology textbook I did not notice any plagiarism in the article. This article has been rated start class on its quality scale and mid-importance. Talk page mostly consists of saying that the article could use more sources.

Week 4 Pacific Farallon Ridge

I am going to expand this article since it is currently very sparse. There are no diagrams of any kind so I plan to add a diagram that shows where the ridge used to exist. There is also only one reference cited and it is to a textbook, so I will add more references that are varied. I also think this article could use more a timeline since this ridge is historical and no longer exists. What I mean by this is when exactly it was in existence and at what time period it disappeared and what is the legacy of this ridge. What parts of it remain today?

Here are some facts I could use from source -McLeod -The ridge was about 10,000 km in length during the late Cretaceous and early tertiary. -About 30 million years ago, the ridge subducted beneath the North American. -San Andreas Fault created when the Farallon plate split up.

Here are some facts I can use from -"spreading ridge behavior" -David Rowley and Christopher Rowan -This ridge was very productive, and it is projected to have produced up to 45% of all oceanic lithosphere since 83 million years ago.

This author of this article also wrote a blog post which is well written - http://all-geo.org/chris_rowan/2014/05/new-paper-spreading-behaviour-of-the-pacific-farallon-ridge-system-since-83-ma/ William Wilcock (talk) 03:43, 24 April 2017 (UTC)

Another source- geological society book

You are low on the article count. I searched "Pacific-Farallon Ridge" in Georef (under Articles and Research Databases on the UW library page) and there were 30+ articles to check. I got a similar listing searching the Web of Science. William Wilcock (talk) 03:43, 24 April 2017 (UTC)

I also found this page https://wn.com/pacific-farallon_ridge William Wilcock (talk) 03:43, 24 April 2017 (UTC)

There may be something here http://serc.carleton.edu/NAGTWorkshops/deepearth/visualizations/farallon.html but it seems mostly focused on the subduction of the Farallon plate William Wilcock (talk) 03:46, 24 April 2017 (UTC)

There is also this famous old article by Tanya Atwater https://websites.pmc.ucsc.edu/~pkoch/EART_206/09-0212/Atwater%2070%20GSABull%2081-3513.pdf William Wilcock (talk) 03:43, 24 April 2017 (UTC)

I recommend looking through the references in the papers you've already listed, and doing a citation search through Web of Science (to see who has referenced your chosen papers) to expand your sources. This will be particularly useful if you find you need more information on a given topic than a single paper provides. Erik (talk) 13:53, 24 April 2017 (UTC)

Overview

The Pacific Farallon Ridge was a spreading ridge during the late Cretaceous that extended 10,000 km in length and separated the Pacific Plate to the west and the Farallon Plate to the east. It ran south from the Pacific-Farallon-Kula triple junction at 51°N to the Pacific-Farallon-Antarctic triple junction at 43°S. As the Farallon Plate subducted obliquely under the North American Plate, the Pacific Farallon Ridge approached and eventually made contact with the North American Plate about 30 million years ago. On average, this ridge had an equatorial spreading rate of 13.5 cm per year until its eventual collision with the North American Plate. In present day, the Pacific Farallon Ridge no longer formally exists since the Farallon Plate has been broken up or subducted beneath the North American Plate, and the ridge has segmented, having been mostly subducted as well. The most notable remnant of the Pacific Farallon Ridge is the 4000 km Pacific- Nazca segment of the East Pacific Rise.

Characteristics

Relative velocity vectors of Pacific, Farallon, and Kula plates 55 million years ago

As a spreading ridge, the Pacific Farallon Ridge was a divergent plate boundary, which is where the two plates are moving away from each other. Partial mantle melting occurs beneath such ridges, which forms new oceanic crust. The Pacific Farallon Ridge was thought to be a particularly productive spreading ridge, and there are estimates that the ridge and its remnants have formed up to 45% of all oceanic lithosphere since 83 million years ago. The spreading rate of the Pacific Farallon Ridge has varied throughout its lifetime with an acceleration of its spreading rate occurring 55 to 48 million years ago, around the same time that a significant portion of the Farallon Plate broke to form the Vancouver Plate. The spreading rate decreased once the ridge made contact with the North American Plate 16 million years ago.

History of the Pacific Farallon Ridge

Formation of the Juan de Fuca (including Explorer and Gorda) and Cocos plates (including Rivera) and of the San Andreas Fault from the Farallon plate

As the Farallon Plate made contact with the North American Plate and began subducting beneath it, it fragmented into the Juan de Fuca Plate and Cocos Plate, and then later fragmented further to form the Rivera Plate. Once the Pacific Farallon Ridge began subducting beneath the North American Plate, the remains of the Farallon Plate broke apart to form the Monterey, Arguello, Magdalena, and Guadelupe Microplates, and the southern portion of the ridge rotated in a clockwise manner. The contact of the ridge with North America marked a transition of the Pacific Farallon Ridge from being a globally oriented spreading ridge system to a locally oriented one. The distinction between these systems is that slab pull and gravitational gliding forces determine the characteristics of the globally oriented whereas those of the locally oriented are influenced by the contact of the ridge with the North American Plate. As the Pacific Farallon Ridge began its subduction underneath the North American plate 30 million years ago, its southern segment, the East Pacific Rise continued spreading. The East Pacific Rise did not begin its subduction under the North American Plate until 20 million years ago, and the presently surviving portion of the East Pacific Rise is the Pacific-Nazca segment. The present-day spreading from the East Pacific Rise dominates the spreading regime in the Central and South Pacific.