South American Plate
The South American Plate is the 7th-largest of the 52 plates in the PB2002 plate model, covering 41.8 million km² (16.1 million sq mi), or 8.2% of Earth’s surface. South America and the South Atlantic floor west of the Mid-Atlantic Ridge.
- Area
- 41.8 million km² (16.1 million sq mi)
- Share of Earth’s surface
- 8.2%
- Speed across the plate
- 0.9 to 1.3 cm a year (0.4 to 0.5 in)
- Direction at its center
- Toward the north-northwest
- Length of its edges
- 35,540 km (22,080 mi)
- Neighboring plates
- 9
- Edges by type
- 33% convergent · 31% divergent · 36% transform
- Volcanoes on it
- 108 active in the past ~12,000 years
What happens at its edges
The Nazca Plate sinks beneath its western edge along the Peru–Chile Trench. That collision raised the Andes and feeds their volcanoes, and it produced the largest earthquake ever recorded, in Chile in 1960.
In the east it moves away from Africa along the Mid-Atlantic Ridge, which is how the South Atlantic opened as the two continents separated.
How fast it moves, and which way
At its center (21.6°S, 45.3°W) the South American Plate moves about 1.3 cm (0.5 in) a year toward the north-northwest. Because a plate turns around a pole rather than sliding in a straight line, the speed changes across it: from 0.9 cm (0.4 in) a year to 1.3 cm (0.5 in) a year, with an area-weighted average of 1.2 cm a year. That average makes it the 49th fastest of the 52 plates.
These figures are measured against the average motion of all the plates together (the “no-net-rotation” frame), which is how plate speeds are usually quoted. Measured against the African Plate instead, the South American Plate moves about 3.4 cm (1.3 in) a year toward the west at its center.
In the model it rotates about a pole at 28.9°S, 125.8°W at 0.121° per million years. The speeds are averages over years to millions of years of measurement; earthquakes move the ground near a boundary in sudden steps instead.
Neighboring plates and boundaries
Its edges run for 35,540 km (22,080 mi): 33% convergent, where plates move together; 31% divergent, where they move apart; and 36% transform, where they slide past each other. It sinks beneath the Caribbean Plate and Sandwich Plate at subduction zones. The Nazca Plate and Antarctic Plate sink beneath it.
| Neighbor | Shared edge | Boundary types | Relative speed |
|---|---|---|---|
| African Plate | 14,970 km (9,300 mi) | Divergent 55% · Transform 45% | 3.2 cm a yearup to 3.4 cm |
| Nazca Plate | 4,300 km (2,670 mi) | Convergent 100% | 7.8 cm a yearup to 8.1 cm |
| Scotia Plate | 3,430 km (2,130 mi) | Transform 52% · Convergent 40% · Divergent 8% | 0.5 cm a yearup to 0.5 cm |
| Altiplano Plate | 2,960 km (1,840 mi) | Convergent 52% · Divergent 38% · Transform 9% | 1.3 cm a yearup to 1.8 cm |
| Antarctic Plate | 2,710 km (1,680 mi) | Transform 52% · Convergent 27% · Divergent 21% | 1.8 cm a yearup to 2.1 cm |
| North Andes Plate | 2,370 km (1,470 mi) | Convergent 66% · Transform 33% | 0.9 cm a yearup to 0.9 cm |
| Caribbean Plate | 2,270 km (1,410 mi) | Convergent 53% · Transform 47% | 1.9 cm a yearup to 2.0 cm |
| North American Plate | 1,690 km (1,050 mi) | Divergent 59% · Transform 26% · Convergent 16% | 0.2 cm a yearup to 0.3 cm |
| Sandwich Plate | 840 km (520 mi) | Convergent 94% · Transform 6% | 7.4 cm a yearup to 8.4 cm |
Relative speed is how fast the two plates move against each other along their shared edge, averaged over its length.
Countries and territories on the South American Plate
7 lie entirely on it; the other 9 are split between plates. The share is the part of each country’s land on this plate.
- Brazil all
- Argentina all
- Peru about 78%
- Venezuela about 87%
- Bolivia about 67%
- Chile about 88%
- Colombia about 57%
- Paraguay all
- Guyana all
- Uruguay all
- Ecuador about 61%
- Suriname all
- France (French Guiana) about 13%
- Falkland Islands all
- South Georgia and the South Sandwich Islands about 93%
- Trinidad and Tobago about 48%
Volcanoes on the South American Plate
The Smithsonian Global Volcanism Program lists 108 volcanoes on this plate that have been active in roughly the past 12,000 years. The most recent eruptions on record:
- Reventador Ecuador, 2026
- Sangay Ecuador, 2026
- Lascar Chile, 2026
- Planchon-Peteroa Chile, 2025
- Villarrica Chile, 2025
- Copahue Chile and Argentina, 2024
Where the edges are blurred
Parts of this plate lie in the Peru, Puna-Sierras Pampeanas and west central Atlantic zones, which the model marks as broad belts of deformation rather than sharp plate edges. There the motion between plates is spread over many faults, and a single boundary line is a simplification.
Sources
Outline, area, boundary types and motion: Bird, P. (2003), An updated digital model of plate boundaries, Geochemistry Geophysics Geosystems, 4(3), 1027, doi:10.1029/2001GC000252. Released by its author into the public domain (CC0 1.0). Areas are the model’s published figures; speeds, directions, boundary lengths and countries are calculated from its outlines, boundary steps and rotation poles.
Volcanoes: Global Volcanism Program, Smithsonian Institution, Volcanoes of the World (v. 5.4.0). Country outlines: Natural Earth.