Polynesia
What tectonic plate is Samoa on?
Samoa sits entirely on the Pacific Plate.
- Plates
- 1
- M6.5+ quakes since 1900
- 4
- Holocene volcanoes
- 2
- Land area
- 2,702 km²
Plates under Samoa
Share of Samoa's land area on each plate (PB2002 model, Natural Earth outlines).
Plate boundaries
3 plate boundaries run through or along Samoa: the Tonga-Pacific boundary (convergent, about 19.3 cm/yr), the Pacific-Niuafo'ou boundary (divergent, about 13.7 cm/yr) and the Tonga-Niuafo'ou boundary (divergent, about 6.2 cm/yr).
- Tonga and Pacific: convergent, 19.3 cm/yr
- Pacific and Niuafo'ou: divergent, 13.7 cm/yr
- Tonga and Niuafo'ou: divergent, 6.2 cm/yr
The fastest of these is the Tonga-Pacific boundary, where the plates move about 19.3 cm/yr relative to each other. That is faster than fingernails grow.
Earthquakes in Samoa
Large earthquakes are uncommon in Samoa. Since 1900 the USGS has recorded 4 of magnitude 6.5 or more in or just off the country.
| Earthquake | Magnitude | Year | Depth | Plate |
|---|---|---|---|---|
| Samoa Earthquake | M8.1 | 2009 | 18 km | Pacific |
| Samoa-Tonga Earthquake | M8.0 | 1917 | 15 km | Tonga |
| 103 km SW of Gataivai, Samoa | M6.6 | 1952 | 15 km | Pacific |
| 154 km SSW of Matavai, Samoa | M6.5 | 1933 | 15 km | Pacific |
Volcanoes in Samoa
The Smithsonian Global Volcanism Program lists 2 volcanoes active in the last 12,000 years in Samoa.
Frequently asked questions
What tectonic plate is Samoa on?
Samoa sits entirely on the Pacific Plate.
Is Samoa on a plate boundary?
3 plate boundaries run through or along Samoa: the Tonga-Pacific boundary (convergent, about 19.3 cm/yr), the Pacific-Niuafo'ou boundary (divergent, about 13.7 cm/yr) and the Tonga-Niuafo'ou boundary (divergent, about 6.2 cm/yr).
Does Samoa get earthquakes?
Large earthquakes are uncommon in Samoa. Since 1900 the USGS has recorded 4 of magnitude 6.5 or more in or just off the country. The largest was the M8.1 Samoa Earthquake in 2009.
Are there volcanoes in Samoa?
The Smithsonian Global Volcanism Program lists 2 volcanoes active in the last 12,000 years in Samoa.