Scotia Plate

Scotia Plate
Scotia Plate
Type	Minor
Approximate area	1,651,000 km2 (637,000 sq mi)
Movement1	West
Speed1	25mm/year
Features	Drake Passage, Scotia Sea, and South Georgia
	1Relative to the African Plate

The Scotia Plate (Spanish: Placa Scotia) is a minor tectonic plate on the edge of the South Atlantic and Southern oceans. Thought to have formed during the early Eocene with the opening of the Drake Passage that separates Antarctica and South America,^[2] it is a minor plate whose movement is largely controlled by the two major plates that surround it: the Antarctic Plate and the South American Plate.^[3] The Scotia Plate takes its name from the steam yacht Scotia of the Scottish National Antarctic Expedition (1902–04), the expedition that made the first bathymetric study of the region.^[4]

Roughly rhomboid, extending between 50°S 70°W / 50°S 70°W / -50; -70 and 63°S 20°W / 63°S 20°W / -63; -20, the plate is 800 km (500 mi) wide and 3,000 km (1,900 mi) long. It is moving WSW at 2.2 cm (0.87 in)/year and the South Sandwich Plate is moving east at 5.5 cm (2.2 in)/year in an absolute reference frame.^[5] Its boundaries are defined by the East Scotia Ridge, the North Scotia Ridge, the South Scotia Ridge, and the Shackleton Fracture Zone. ^[6]

The Scotia Plate is made of oceanic crust and continental fragments now distributed around the Scotia Sea. Before the formation of the plate began 40 million years ago (40Ma), these fragments formed a continuous landmass from Patagonia to the Antarctic Peninsula along an active subduction margin.^[5] At present, the plate is almost completely submerged, with only the small exceptions of South Georgia on its northeastern edge and the southern tip of South America.^[7]

^ "SFT and the Earth's Tectonic Plates". Los Alamos National Laboratory. Archived from the original on 29 July 2015. Retrieved 17 July 2015.
^ Livermore et al. 2005, 5. Eocene opening, pp. 465, 467
^ Livermore et al. 2005, 2. South America-Antarctica plate tectonics, p. 460
^ Dalziel et al. 2013, The Scotia Arc in space and time, pp. 768–769
^ ^a ^b Giner-Robles et al. 2003, 2. Geological setting, pp. 179–181
^ Riley et al. 2019, P137
^ Thomas, Livermore & Pollitz 2003, ^{[page needed]}

[1] "SFT and the Earth's Tectonic Plates". Los Alamos National Laboratory. Archived from the original on 29 July 2015. Retrieved 17 July 2015.

[2] Livermore et al. 2005, 5. Eocene opening, pp. 465, 467

[3] Livermore et al. 2005, 2. South America-Antarctica plate tectonics, p. 460

[Dalziel-etal-2013-spacetime-4] Dalziel et al. 2013, The Scotia Arc in space and time, pp. 768–769

[Giner-etal-Geolset-5] Giner-Robles et al. 2003, 2. Geological setting, pp. 179–181

[6] Riley et al. 2019, P137

[Thomas-7] Thomas, Livermore & Pollitz 2003, ^{[page needed]}

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