Scotia Plate
The Scotia Plate (Spanish: Placa Scotia) is a 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 South America from Antarctica,[2] it is a minor plate whose movement is largely controlled by the two major plates that surround it: the South American Plate and the Antarctic 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]
Scotia Plate | |
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Type | Minor |
Approximate area | 1,651,000 km2 (637,000 sq mi)[1] |
Movement1 | West |
Speed1 | 25mm/year |
Features | Scotia Sea, South Georgia Island, Drake Passage |
1Relative to the African Plate |
Roughly rhomboid, extending between 50°S 70°W and 63°S 20°W, 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]
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 Island on its northeastern edge and the southern tip of South America.[6]