Plate data: Bird (2003), PB2002, converted by Hugo Ahlenius, Nordpil (ODC-By 1.0). Land: Natural Earth (India POV).
The South American Plate carries South America and the western half of the South Atlantic floor. Along the Peru-Chile trench, the oceanic Nazca Plate is pushed under the continental edge of the South American Plate, and the overriding plate is lifted up into the Andes (USGS). In the Pachapaqui mining area in Peru, this convergence has deformed and pushed up limestone strata into towering peaks (USGS).
On 9 June 1994, a magnitude 8.3 earthquake struck about 320 km northeast of La Paz, Bolivia, at a depth of 636 km. USGS calls it one of the deepest and largest subduction earthquakes recorded in South America. On the east side, the Mid-Atlantic Ridge separates the plate from Africa. The matching shapes of the two coasts were one of the clues behind continental drift.
PB2002 does not treat the whole Andes as part of this plate. Bird (2003) splits off an Altiplano Plate in the central Andes, reaching from the Peru-Chile trench to the thrust belt on the eastern slope of the mountains, so on this map La Paz sits on the Altiplano Plate.1 In the combined GPS and geologic model of Lamb (2000), which Bird uses, the Altiplano block moves about 15 mm per year toward N59E relative to South America. North and south of it, Bird marks the Peru and Puna-Sierras Pampeanas orogens. There the Nazca Plate subducts almost horizontally, which has shut off those parts of the Andean volcanic arc.
In the north, a separate North Andes Plate covers the northern Andes in Colombia, Ecuador and Venezuela. GPS results from the Central And South America (CASA) project show it moving relative to South America with a dextral component of 7 to 8 mm per year and a compressive component of 4 to 5 mm per year (Bird 2003).
South American Plate in numbers
Measured from its PB2002 outline, the South American Plate covers about 41.8 million km², or 8.2% of the
Earth's surface. That makes it number 7 by area of the 52 plates in the model.
It spans from 61°S to 19°N and from 82°W to 0°W.
Its edge is about 35,550 km long, mostly transform:
31.4%divergentDivergent boundary. Plates pull away from each other and new crust forms between them. Source (11,173 km)
, 33%convergentConvergent boundary. Plates move toward each other and crust is destroyed as one plate dives under another. Source (11,749 km)
and 35.5%transformTransform boundary. Plates slide horizontally past each other. Crust is neither made nor destroyed. Source (12,628 km)
.
Countries whose main landmass sits on this plate: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Is., France, Guyana, Paraguay, Peru, Suriname, Trinidad and Tobago, Uruguay and Venezuela. Countries that straddle a boundary
are listed under the plate that holds the center of their largest landmass.
South American Plate fact table
South American Plate at a glance, computed from PB2002
Along its boundaries it moves a mean 2.9 cm/yr relative to its neighbors, fastest against the Sandwich Plate. Bird (2003)
Neighboring plates Neighbors. Plates that share a boundary with this plate. Most plate movement happens along these narrow zones between plates. Source
The South American Plate shares a boundary with 9 plates in PB2002, longest shared edge first.
The longest, about 14,985 km, is with the African Plate; the shortest, about 845 km, is with the Sandwich Plate.
Placed by point-in-polygon test on the PB2002 plate outlines (Bird 2003); not stated by USGS or Bird.
South American Plate FAQ
How big is the South American Plate?
About 41.8 million km², or 8.2% of the Earth's surface, measured from its PB2002 outline. It ranks 7 of 52 plates by area.
Which plates border the South American Plate?
9 plates: African Plate, Nazca Plate, Scotia Plate, Altiplano Plate, Antarctic Plate, North Andes Plate, Caribbean Plate, North American Plate and Sandwich Plate.
What kind of plate boundaries does the South American Plate have?
Mostly transform boundaries. 31.4% divergent, 33% convergent, 35.5% transform, of 35,550 km in total.
How fast does the South American Plate move?
Relative to its neighbors, a mean 29.3 mm/yr (2.9 cm/yr) along its boundaries in PB2002. The fastest boundary is with the Sandwich Plate.
