Pacific Plate

The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million km2 (40 million sq mi), it is the largest tectonic plate.[2]

Pacific Plate
TypeMajor
Approximate area103,300,000 km2 (39,900,000 sq mi)[1]
Movement1north-west
Speed156–102 mm (2.2–4.0 in)/year
FeaturesBaja California Peninsula, Southern California, Hawaiian Islands, New Zealand, Solomon Islands archipelago, Southeast Alaska, Pacific Ocean
1Relative to the African Plate

The Pacific Plate contains an interior hot spot forming the Hawaiian Islands.[3]

Hillis and Müller are reported to consider the Bird's Head Plate to be moving in unison with the Pacific Plate.[4] Bird considers them to be unconnected.[5]

Boundaries

The north-eastern side is a divergent boundary with the Explorer Plate, the Juan de Fuca Plate and the Gorda Plate forming respectively the Explorer Ridge, the Juan de Fuca Ridge and the Gorda Ridge. In the middle of the eastern side is a transform boundary with the North American Plate along the San Andreas Fault, and a boundary with the Cocos Plate. The south-eastern side is a divergent boundary with the Nazca Plate forming the East Pacific Rise.

The southern side is a divergent boundary with the Antarctic Plate forming the Pacific-Antarctic Ridge.

The western side, the plate is bounded by the Okhotsk Plate at the Kuril-Kamchatka Trench and the Japan Trench, forms a convergent boundary by subducting under the Philippine Sea Plate creating the Mariana Trench, has a transform boundary with the Caroline Plate, and has a collision boundary with the North Bismarck Plate.

In the south-west, the Pacific Plate has a complex but generally convergent boundary with the Indo-Australian Plate, subducting under it north of New Zealand forming the Tonga Trench and the Kermadec Trench. The Alpine Fault marks a transform boundary between the two plates, and further south the Indo-Australian Plate subducts under the Pacific Plate forming the Puysegur Trench. The southern part of Zealandia, which is to the east of this boundary, is the plate's largest block of continental crust.

The northern side is a convergent boundary subducting under the North American Plate forming the Aleutian Trench and the corresponding Aleutian Islands.

Paleo-geology of the Pacific Plate

The Pacific Plate is almost entirely oceanic crust, but it contains some continental crust in New Zealand, Baja California, and coastal California.[3]

The Pacific Plate has the distinction of showing one of the largest areal sections of the oldest members of seabed geology being entrenched into eastern Asian oceanic trenches. A geologic map of the Pacific Ocean seabed shows not only the geologic sequences, and associated Ring of Fire zones on the ocean's perimeters, but the various ages of the seafloor in a stairstep fashion, youngest to oldest, the oldest being consumed into the Asian oceanic trenches. The oldest part disappearing by way of the plate tectonics cycle is early-Cretaceous (145 to 137 million years ago).[6]

All maps of the Earth's ocean floor geology show ages younger than 145 million years, only about 1/30 of the Earth's 4.55 billion year history.

gollark: I do like having an ISP which, while quite slow, happily lets us just download terabytes a month with no problems.
gollark: Oh wow, that is pretty bad.
gollark: Internet connection speeds are mostly measured in Mbps. Which is frustrating, because I mostly use MB.
gollark: In many cases, it's more useful to have a somewhat large binary *now* than a hyperoptimized small one much later.
gollark: We already ran into netsplits or something after one of the two servers went down. This is very IRC.

References
  1. "Here are the Sizes of Tectonic or Lithospheric Plates". Archived from the original on 2016-06-05. Retrieved 2015-05-04.
  2. "SFT and the Earth's Tectonic Plates". Los Alamos National Laboratory. Archived from the original on 17 February 2013. Retrieved 27 February 2013.
  3. Wolfgang Frisch; Martin Meschede; Ronald C. Blakey (2 November 2010). Plate Tectonics: Continental Drift and Mountain Building. Springer Science & Business Media. pp. 11–12. ISBN 978-3-540-76504-2.
  4. Hillis, R. R.; Müller, R. D. (2003). Evolution and Dynamics of the Australian Plate. Boulder, CO: Geological Society of America. p. 363. ISBN 0-8137-2372-8.
  5. Bird, Peter (2003). "An updated digital model of plate boundaries". Geochemistry, Geophysics, Geosystems. 4 (3): 1027. Bibcode:2003GGG.....4.1027B. doi:10.1029/2001GC000252.
  6. "Age of the Ocean Floor". Archived from the original on 2016-08-06. Retrieved 2009-02-07.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.