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Juan de Fuca Plate

April 01, 2023

This article is about the entire Juan de Fuca Plate, or more specifically the middle fragment. For the northern fragment, see Explorer Plate. For the southern fragment, see Gorda Plate.
For the soccer cup, see Juan de Fuca Plate (soccer).

The Juan de Fuca Plate is a small tectonic plate (microplate) generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American Plate at the Cascadia subduction zone.[2] It is named after the explorer of the same name. One of the smallest of Earth's tectonic plates, the Juan de Fuca Plate is a remnant part of the once-vast Farallon Plate, which is now largely subducted underneath the North American Plate.

Juan de Fuca Plate
TypeMicro
Approximate area250,000 km2 (96,000 sq mi)[1]
Movement1North-east
Speed126 mm/year (1.0 in/year)
FeaturesPacific Ocean
1Relative to the African Plate
Cutaway of the Juan de Fuca Plate
Image source: USGS

In plate tectonic reconstructions, the Juan de Fuca Plate is referred to as the Vancouver Plate between the break-up of the Farallon Plate c. 55–52 Ma and the activation of the San Andreas Fault c. 30 Ma.[3]

Origins

The Juan de Fuca Plate system has its origins with Panthalassa's oceanic basin and crust. This oceanic crust has primarily been subducted under the North American Plate, and the Eurasian Plate. Panthalassa's oceanic plate remnants are understood to be the Juan de Fuca, Gorda, Cocos and the Nazca plates, all four of which were part of the Farallon Plate.

Extent

 
A map of the Juan de Fuca Plate with noted seismic incidents, including the 2001 Nisqually earthquake

The Juan de Fuca Plate is bounded on the south by the Blanco Fracture Zone (running northwest off the coast of Oregon), on the north by the Nootka Fault (running southwest off Nootka Island, near Vancouver Island, British Columbia) and along the west by the Pacific Plate (which covers most of the Pacific Ocean and is the largest of Earth's tectonic plates). The Juan de Fuca Plate itself has since fractured into three pieces, and the name is applied to the entire plate in some references, but in others only to the central portion. The three fragments are differentiated as such: the piece to the south is known as the Gorda Plate and the piece to the north is known as the Explorer Plate. The separate pieces are demarcated by the large offsets of the undersea spreading zone.

Volcanism

This subducting plate system has formed the Cascade Range, the Cascade Volcanic Arc, and the Pacific Ranges, along the west coast of North America from southern British Columbia to northern California. These in turn are part of the Pacific Ring of Fire, a much larger-scale volcanic feature that extends around much of the rim of the Pacific Ocean.

Earthquakes

The last megathrust earthquake at the Cascadia subduction zone was the 1700 Cascadia earthquake, estimated to have a moment magnitude of 8.7 to 9.2. Based on carbon dating of local tsunami deposits, it is inferred to have occurred around 1700.[4] Evidence of this earthquake is also seen in the ghost forest along the bank of the Copalis River in Washington. The rings of the dead trees indicate that they died around 1700, and it is believed that they were killed when the earthquake occurred and sank the ground beneath them causing the trees to be flooded by saltwater.[5] Japanese records indicate that a tsunami occurred in Japan on 26 January 1700, which was likely caused by this earthquake.[6]

In 2008, small earthquakes were observed within the Juan de Fuca Plate. The unusual quakes were described as "more than 600 quakes over the past 10 days in a basin 150 miles [240 km] southwest of Newport". The quakes were unlike most quakes in that they did not follow the pattern of a large quake, followed by smaller aftershocks; rather, they were simply a continual deluge of small quakes. Furthermore, they did not occur on the tectonic plate boundary, but rather in the middle of the plate. The subterranean quakes were detected on hydrophones, and scientists described the sounds as similar to thunder, and unlike anything previously recorded.[7]

Carbon sequestration potential

The basaltic formations of the Juan de Fuca Plate could potentially be suitable for long-term CO2 sequestration as part of a carbon capture and storage (CCS) system. Injection of CO2 would lead to the formation of stable carbonates. It is estimated that 100 years of US carbon emissions (at current rate) could be stored securely, without risk of leakage back into the atmosphere.[8][9]

Tearing

In 2019, scientists from the University of California, Berkeley, published a study in Geophysical Research Letters in which they reported that by utilizing data from over 30,000 seismic waves and 217 earthquakes to create a three-dimensional map, they had revealed the existence of a hole in the subducted part of the Juan de Fuca Plate, and speculated that the hole is an indication of a 150 kilometres (93 mi) deep tear in the plate along a "preexisting zone of weakness". According to William B. Hawley and Richard M. Allen, the authors of the study, the hole may be the cause of volcanism and earthquakes on the plate, and is causing deformation of the offshore part of the plate. The deformation may cause the plate to fragment, with the remaining un-subducted small pieces becoming attached to other plates nearby.[10][11]

See also

References

  1. ^ "Sizes of Tectonic or Lithospheric Plates". Geology.about.com. 5 March 2014. Retrieved 6 January 2016.
  2. ^ How Many Tectonic Plates Are There?
  3. ^ Seton, M.; Müller, R.D.; Zahirovic, S.; Gaina, C.; Torsvik, T.; Shephard, G.; Talsma, A.; Gurnis, M.; Maus, S.; Chandler, M. (2012). "Global continental and ocean basin reconstructions since 200Ma". Earth-Science Reviews. 113 (3): 212–270. Bibcode:2012ESRv..113..212S. doi:10.1016/j.earscirev.2012.03.002. Retrieved 23 October 2016.
  4. ^ Wong, Florence L. "Seaside, Oregon, Tsunami Pilot Study GIS, USGS Data Series 236, home page". pubs.usgs.gov. Retrieved 15 April 2017.
  5. ^ Schulz, Kathryn (June 20, 2015). "The Earthquake That Will Devastate the Pacific Northwest". The New Yorker.
  6. ^ Satake, Kenji; Wang, Kelin; Atwater, Brian F. (1 November 2003). "Fault slip and seismic moment of the 1700 Cascadia earthquake inferred from Japanese tsunami descriptions". Journal of Geophysical Research: Solid Earth. 108 (B11): 2535. Bibcode:2003JGRB..108.2535S. doi:10.1029/2003JB002521. ISSN 2156-2202.
  7. ^ "Unusual Earthquake Swarm Off Oregon Coast Puzzles Scientists". Science News. ScienceDaily. 2008-04-14.
  8. ^ Goldberg, D. S. (2008-07-22). "Carbon dioxide sequestration in deep-sea basalt". Proceedings of the National Academy of Sciences. 105 (29): 9920–9925. Bibcode:2008PNAS..105.9920G. doi:10.1073/pnas.0804397105. PMC 2464617. PMID 18626013.
  9. ^ Fairley, Jerry (January 2013). "Sub-seafloor Carbon Dioxide Storage Potential on the Juan de Fuca Plate, Western North America". Energy Procedia. 37: 5248–5257. doi:10.1016/j.egypro.2013.06.441.
  10. ^ Hawley, William B.; Allen, Richard M. (2019). "The Fragmented Death of the Farallon Plate". Geophysical Research Letters. 46 (13): 7386–7394. Bibcode:2019GeoRL..46.7386H. doi:10.1029/2019GL083437.
  11. ^ Nield, David, (July 31, 2019) "A Tectonic Plate Under Oregon Is Being Slowly Ripped Apart", Science Alert

External links

  • National Geographic on Japanese records verifying an American earthquake
  • Cascadia tectonic history with map

April 01, 2023
juan, fuca, plate, this, article, about, entire, more, specifically, middle, fragment, northern, fragment, explorer, plate, southern, fragment, gorda, plate, soccer, soccer, small, tectonic, plate, microplate, generated, from, juan, fuca, ridge, that, subducti. This article is about the entire Juan de Fuca Plate or more specifically the middle fragment For the northern fragment see Explorer Plate For the southern fragment see Gorda Plate For the soccer cup see Juan de Fuca Plate soccer The Juan de Fuca Plate is a small tectonic plate microplate generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American Plate at the Cascadia subduction zone 2 It is named after the explorer of the same name One of the smallest of Earth s tectonic plates the Juan de Fuca Plate is a remnant part of the once vast Farallon Plate which is now largely subducted underneath the North American Plate Juan de Fuca PlateTypeMicroApproximate area250 000 km2 96 000 sq mi 1 Movement1North eastSpeed126 mm year 1 0 in year FeaturesPacific Ocean1Relative to the African PlateCutaway of the Juan de Fuca PlateImage source USGS In plate tectonic reconstructions the Juan de Fuca Plate is referred to as the Vancouver Plate between the break up of the Farallon Plate c 55 52 Ma and the activation of the San Andreas Fault c 30 Ma 3 Contents 1 Origins 2 Extent 3 Volcanism 4 Earthquakes 5 Carbon sequestration potential 6 Tearing 7 See also 8 References 9 External linksOrigins EditThe Juan de Fuca Plate system has its origins with Panthalassa s oceanic basin and crust This oceanic crust has primarily been subducted under the North American Plate and the Eurasian Plate Panthalassa s oceanic plate remnants are understood to be the Juan de Fuca Gorda Cocos and the Nazca plates all four of which were part of the Farallon Plate Extent Edit A map of the Juan de Fuca Plate with noted seismic incidents including the 2001 Nisqually earthquake The Juan de Fuca Plate is bounded on the south by the Blanco Fracture Zone running northwest off the coast of Oregon on the north by the Nootka Fault running southwest off Nootka Island near Vancouver Island British Columbia and along the west by the Pacific Plate which covers most of the Pacific Ocean and is the largest of Earth s tectonic plates The Juan de Fuca Plate itself has since fractured into three pieces and the name is applied to the entire plate in some references but in others only to the central portion The three fragments are differentiated as such the piece to the south is known as the Gorda Plate and the piece to the north is known as the Explorer Plate The separate pieces are demarcated by the large offsets of the undersea spreading zone Volcanism EditThis subducting plate system has formed the Cascade Range the Cascade Volcanic Arc and the Pacific Ranges along the west coast of North America from southern British Columbia to northern California These in turn are part of the Pacific Ring of Fire a much larger scale volcanic feature that extends around much of the rim of the Pacific Ocean Earthquakes EditThe last megathrust earthquake at the Cascadia subduction zone was the 1700 Cascadia earthquake estimated to have a moment magnitude of 8 7 to 9 2 Based on carbon dating of local tsunami deposits it is inferred to have occurred around 1700 4 Evidence of this earthquake is also seen in the ghost forest along the bank of the Copalis River in Washington The rings of the dead trees indicate that they died around 1700 and it is believed that they were killed when the earthquake occurred and sank the ground beneath them causing the trees to be flooded by saltwater 5 Japanese records indicate that a tsunami occurred in Japan on 26 January 1700 which was likely caused by this earthquake 6 In 2008 small earthquakes were observed within the Juan de Fuca Plate The unusual quakes were described as more than 600 quakes over the past 10 days in a basin 150 miles 240 km southwest of Newport The quakes were unlike most quakes in that they did not follow the pattern of a large quake followed by smaller aftershocks rather they were simply a continual deluge of small quakes Furthermore they did not occur on the tectonic plate boundary but rather in the middle of the plate The subterranean quakes were detected on hydrophones and scientists described the sounds as similar to thunder and unlike anything previously recorded 7 Carbon sequestration potential EditThe basaltic formations of the Juan de Fuca Plate could potentially be suitable for long term CO2 sequestration as part of a carbon capture and storage CCS system Injection of CO2 would lead to the formation of stable carbonates It is estimated that 100 years of US carbon emissions at current rate could be stored securely without risk of leakage back into the atmosphere 8 9 Tearing EditIn 2019 scientists from the University of California Berkeley published a study in Geophysical Research Letters in which they reported that by utilizing data from over 30 000 seismic waves and 217 earthquakes to create a three dimensional map they had revealed the existence of a hole in the subducted part of the Juan de Fuca Plate and speculated that the hole is an indication of a 150 kilometres 93 mi deep tear in the plate along a preexisting zone of weakness According to William B Hawley and Richard M Allen the authors of the study the hole may be the cause of volcanism and earthquakes on the plate and is causing deformation of the offshore part of the plate The deformation may cause the plate to fragment with the remaining un subducted small pieces becoming attached to other plates nearby 10 11 See also EditAstoria Fan Cascadia Channel Geology of the Pacific Northwest Plate tectonicsReferences Edit Sizes of Tectonic or Lithospheric Plates Geology about com 5 March 2014 Retrieved 6 January 2016 How Many Tectonic Plates Are There Seton M Muller R D Zahirovic S Gaina C Torsvik T Shephard G Talsma A Gurnis M Maus S Chandler M 2012 Global continental and ocean basin reconstructions since 200Ma Earth Science Reviews 113 3 212 270 Bibcode 2012ESRv 113 212S doi 10 1016 j earscirev 2012 03 002 Retrieved 23 October 2016 Wong Florence L Seaside Oregon Tsunami Pilot Study GIS USGS Data Series 236 home page pubs usgs gov Retrieved 15 April 2017 Schulz Kathryn June 20 2015 The Earthquake That Will Devastate the Pacific Northwest The New Yorker Satake Kenji Wang Kelin Atwater Brian F 1 November 2003 Fault slip and seismic moment of the 1700 Cascadia earthquake inferred from Japanese tsunami descriptions Journal of Geophysical Research Solid Earth 108 B11 2535 Bibcode 2003JGRB 108 2535S doi 10 1029 2003JB002521 ISSN 2156 2202 Unusual Earthquake Swarm Off Oregon Coast Puzzles Scientists Science News ScienceDaily 2008 04 14 Goldberg D S 2008 07 22 Carbon dioxide sequestration in deep sea basalt Proceedings of the National Academy of Sciences 105 29 9920 9925 Bibcode 2008PNAS 105 9920G doi 10 1073 pnas 0804397105 PMC 2464617 PMID 18626013 Fairley Jerry January 2013 Sub seafloor Carbon Dioxide Storage Potential on the Juan de Fuca Plate Western North America Energy Procedia 37 5248 5257 doi 10 1016 j egypro 2013 06 441 Hawley William B Allen Richard M 2019 The Fragmented Death of the Farallon Plate Geophysical Research Letters 46 13 7386 7394 Bibcode 2019GeoRL 46 7386H doi 10 1029 2019GL083437 Nield David July 31 2019 A Tectonic Plate Under Oregon Is Being Slowly Ripped Apart Science AlertExternal links EditNational Geographic on Japanese records verifying an American earthquake Cascadia tectonic history with map Retrieved from https en wikipedia org w index php title Juan de Fuca Plate amp oldid 1139963080, wikipedia, wiki, book, books, library,

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