User:Daothao/sandbox

(edit 5/8 Added the sections from my OneNote, whoops.)

Week 5/6 First Draft

Daothao/sandbox
Type	Microplate
Approximate area	18,000 km2 (6950 sq mi)
Movement1	north-east
Speed1	Nearly 0 mm/year
Features	Pacific Ocean
1Relative to the African plate

Explorer Plate

The Explorer Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Vancouver Island, Canada and is partially subducted under the North American Plate. Along with the Juan De Fuca Plate and Gorda Plate, the Explorer Plate is a remnant of the Farallon Plate which subducted under the North American Plate. The Explorer Plate separated from the Juan De Fuca plate roughly 4 million years ago. The average depth of the Explorer plate is roughly 2,400 m (1.49 mi) in the southern, smoother half and rises up to an average depth of 2,000 m (1.24 mi) in the northern half which varies highly over an oceanic basin between 1,400 and 2,200 m (.87 and 1.38 mi) in depth.

Boundaries

The eastern boundary of the Explorer Plate is partially subducted under the North American Plate. The southern boundary is a collection of transform faults, the Sovanco Fracture Zone, separating the Explorer Plate from the Pacific Plate. To the southeast is another transform boundary, the Nootka Fault, which separates the Explorer Plate from the Juan de Fuca Plate and forming a triple junction with the North American Plate. To the northwest is a divergent boundary with the Pacific Plate forming the Explorer Ridge, and the Winona Basin located within the northwest boundaries and the Pacific continental shelf. The Queen Charlotte triple junction is located where the Pacific plate and North American Plate meets with the Explorer Plate.

Bathymetric profile of Explorer Ridge region

Formation and Evolution

Breaking away from the Juan De Fuca Plate 4 million years ago involved a separation in their shared direction, with the Juan De Fuca continuing North-East at 26 mm/year (1 in/year) and the Explorer plate stalling or moving slowly North nearly 0 mm/year. The Nootka Fault zone is a fault boundary zone that defines the boundary between the Juan De Fuca Plate and the Explorer Plate as it has varied greatly since their separation. Forming the Nookta Fault and the shearing of plate boundaries has caused a clockwise rotation, reorienting the Sovanco Fracture Zone northwards along the North American Plate and slowing the Explorer Plate’s subduction. The Sovanco Fracture Zone originated as a spreading center offset more than 7 million years ago which show southward movement from the influence of the Explorer ridge and results in uneven spreading eastward unto the Explorer Plate.

Seismic Activity

Being a part of the Pacific Ring of Fire, the seismic activity of the Explorer Plate is high, however, it is comprised of low-intensity events as no earthquake in the region have been recorded past a magnitude of 6.5 however, a swarm of several dozen magnitude 5-6 earthquakes occurred just north of the Seminole Seamount in 2008. The Explorer Plate is the most seismicly active areas of Canada, but is anomalous as most of the seismic activity occurs within the plate's region rather than under the continental edge like other subduction zones. Events are generally centered around the southern and north-western areas where the borders of the plate are in contact with other plates, however the newer ocean crust created at Explorer ridge and Juan de Fuca ridge reduces the rigidity of the region and contributes to the low-intensity of events in the region.

Current State of Subduction

The subducted portion of the plate extends downward to more than 300 km (186 mi) in depth, and as far as mainland Canada. The relative buoyancy of the subducting plate and the underlying mantle may be preventing the Explorer Plate’s ability to subduct.

There is an ongoing debate regarding the process of subduction of the Explorer Plate and how the boundary between the Explorer plate and the North American Plate are defined:

1. The Explorer Plate has stopped and may eventually accrete, fusing with the North American plate as the subduction has fully stopped and will eventually become a plate boundary between the North American Plate and Pacific Plate rather than continuing its subduction.
2. The Explorer Plate consists of two parts with half being fused to the North American Plate and the other half remaining a microplate system.
3. The Explorer Plate will continue its subduction as the process has slowed to a maximum of 20 mm/year, and will continue until the entirety of the plate is subducted.

Week 4: Find your sources

This looks great so far. Erik (talk) 13:48, 24 April 2017 (UTC)

This is a solid start. I would suggest something on the history of the plate - it separated from the Juan de Fuca plate when the Nootka fault formed. When did this happen. Is the Explorer microplate still subducting? What is going to happen to it in the future. Have you searched on Georef for articles. What about more popular articles. If you cover one of the triple junctions are you going to cover the other triple junctions around its edges and the plate boundaries along its edges. I found this link http://americastectonics.weebly.com/juan-de-fuca-explorer-and-gorda-plates.html that might have some good sources William Wilcock (talk) 04:33, 24 April 2017 (UTC)

The image featured obscures the plate by the seismology and I plan on using an editing a picture similar to other pages on tectonic plates such as Juan de Fuca Plate, Pacific Plate, etc. Source image:[1]

I also plan on adding 2-3 sections on:

Seismology:

I plan on moving the current main image here and citing Seismotectonics of the Explorer region, discussing their analysis and findings.

Also, Earthquake Report: Explorer plate is a blog post that is well referenced and includes personal data but I will be looking for similar alternatives.

Morphology and Bathymetry:

There are a number of sources that discuss the morphology of the Explorer plate using different methods such as:

Morphology of the Explorer–Juan de Fuca slab edge in northern Cascadia (using bathymetry)

Tectonic Evolution of the Explorer-Northern Juan de Fuca Region From 8 Ma to the Present (magnetic anomaly data, in conjunction with Sea Beam and SeaMARC II data)

Queen Charlotte Triple junction:

The triple junction seems to be a topic of specific interest and I'll be adding some information from these :

Explorer deformation zone: Evidence of a large shear zone and reorganization of the Pacific–Juan de Fuca–North American triple junction

Ephemeral plate tectonics at the Queen Charlotte triple junction

Specifically noting Explorer plate's contribution/effects, though I might just redirect it to Queen Charlotte Triple Junction page's section on the Explorer plate.

I'll also be including a reference similar to this:

See also: Queen Charlotte Triple Junction

Current bibliography:

Braunmiller, Jochen; Nábělek, John (2002-10-01). "Seismotectonics of the Explorer region". Journal of Geophysical Research: Solid Earth. 107 (B10): 2208. doi:10.1029/2001JB000220. ISSN 2156-2202.

"Earthquake Report: Explorer plate!". Jay Patton online. Retrieved 2017-04-21.

Audet, P.; Bostock, M. G.; Mercier, J.-P.; Cassidy, J. F. (2008-11-01). "Morphology of the Explorer–Juan de Fuca slab edge in northern Cascadia: Imaging plate capture at a ridge-trench-transform triple junction". Geology. 36 (11): 895–898. doi:10.1130/G25356A.1. ISSN 0091-7613.

Botros, Mona; Johnson, H. Paul (1988-09-10). "Tectonic evolution of the Explorer-Northern Juan de Fuca Region from 8 Ma to the present". Journal of Geophysical Research: Solid Earth. 93 (B9): 10421–10437. doi:10.1029/JB093iB09p10421. ISSN 2156-2202.

Dziak, Robert P. (2006-03-01). "Explorer deformation zone: Evidence of a large shear zone and reorganization of the Pacific–Juan de Fuca–North American triple junction". Geology. 34 (3): 213–216. doi:10.1130/G22164.1. ISSN 0091-7613.

Rohr, Kristin M. M.; Furlong, Kevin P. (1995-11-01). "Ephemeral plate tectonics at the Queen Charlotte triple junction". Geology. 23 (11): 1035–1038. doi:10.1130/0091-7613(1995)0232.3.CO;2 (inactive 2022-06-05). ISSN 0091-7613.{{cite journal}}: CS1 maint: DOI inactive as of June 2022 (link)

For Week 3 the Satake citation is an important addition to the Juan de Fuca page William Wilcock (talk) 23:49, 16 April 2017 (UTC)

Week 2: Critique articles

Plate Tectonics:

This article lacks consistent citing of sources, or is unnecessarily reliant on being self-referential. The last paragraph in the introduction and the first in key principles regarding driving force of motion lacks a specific source but is adequately explained and cited further in the article.

Notably, the section of driving force from Earth rotation is flagged as needing additional citations, which seems close to being fulfilled and acts as more of a "conflict area" flag than what it should be used for. The article seems to suffer from several conflicting ideologies and is shorted with "...still subject to debate" throughout. Additionally, the talk page of the article shows the conflicting ideas of what is fact explicitly such as the biased discussion on flood geology. The suggestion on driving force in the talk page similarly was answered with some poignancy, as with several other cases of accused "self-promotion".

The reference "Plate Tectonics: Plate Boundaries". platetectonics.com. Retrieved 12 June 2010." is not a usable source for where it is used as it is a visualizer and a Wikipedia link, not a source of information. The book "Carey, S. W. (1958). "The tectonic approach to continental drift"" seems to be an unreachable symposium transcript, and the sole source without an ISBN.

I found the Carey reference in the UW catalog and it is an important early meeting in the development of plate tectonics (it is in the Development of the Theory section and is an appropriate reference William Wilcock (talk) 23:32, 16 April 2017 (UTC)

Transform Fault:

The article is missing relevant sources for the main "mechanics" sections and the "differences between..", both of which could probably be joined with the last section on transform types and using those sources. Other specific parts such as under the "Examples" section describes their geological location but like citation of sources for the mechanics explained, again can be merged with the earlier section but requiring sources.

The resources and citation of this page has a few key missing information and tying of citations. For example, the first reference is a textbook could use quick links like ISBN. The last two resources are not used directly in the article and should be removed otherwise.

(Edit 4/10: Evidently, I misinterpreted the assignment and only did the Wikipedia module and not the actual evaluation.) Daothao (talk)

I think the assignment was pretty clear. The above review focuses on citations and make some good points that could improve them but it does not address many of the questions listed in the assignment. I liked your comment on the Transform Fault talk page William Wilcock (talk) 23:34, 16 April 2017 (UTC)