Northern America
What tectonic plate is the United States on?
The United States spans 2 tectonic plates: the North American Plate (99%) and the Pacific Plate (1.1%).
- Plates
- 2
- M6.5+ quakes since 1900
- 320
- Holocene volcanoes
- 135
- Land area
- 9.44 million km²
Plates under the United States
Share of the United States's land area on each plate (PB2002 model, Natural Earth outlines).
Plate boundaries
3 plate boundaries run through or along the United States: the Pacific-Juan de Fuca boundary (divergent, about 5.6 cm/yr), the Juan de Fuca-North American boundary (convergent, about 4.0 cm/yr) and the North American-Pacific boundary (convergent, about 5.6 cm/yr).
- Pacific and Juan de Fuca: divergent, 5.6 cm/yr
- Juan de Fuca and North American: convergent, 4.0 cm/yr
- North American and Pacific: convergent, 5.6 cm/yr
The fastest of these is the Pacific-Juan de Fuca boundary, where the plates move about 5.6 cm/yr relative to each other. That is faster than fingernails grow.
Earthquakes in the United States
The United States is one of the most earthquake-prone countries on Earth. The USGS catalog lists 320 earthquakes of magnitude 6.5 or more in or just off the United States since 1900, which ranks it 3 of 213 countries.
| Earthquake | Magnitude | Year | Depth | Plate |
|---|---|---|---|---|
| Prince William Sound, Alaska Earthquake | M9.2 | 1964 | 25 km | North American |
| Western Aleutian Islands (Hawadax/Rat Islands) Earthquake | M8.7 | 1965 | 30 km | North American |
| Unimak Island, Alaska Earthquake | M8.6 | 1946 | 15 km | North American |
| Atka, Alaska Earthquake | M8.6 | 1957 | 25 km | North American |
| Western Aleutian Islands (Hawadax/Rat Islands) Earthquake | M8.3 | 1906 | 110 km | North American |
| Semidi Islands, Alaska Earthquake | M8.2 | 1938 | 35 km | North American |
Volcanoes in the United States
The Smithsonian Global Volcanism Program lists 135 volcanoes active in the last 12,000 years in the United States, the most of any country.
- Great Sitkin Stratovolcano · 1,740 m Last eruption 2026
- Kilauea Shield · 1,222 m Last eruption 2026
- Atka Volcanic Complex Stratovolcano(es) · 1,518 m Last eruption 2025
- Semisopochnoi Stratovolcano · 1,221 m Last eruption 2023
- Kanaga Stratovolcano · 1,307 m Last eruption 2023
- Shishaldin Stratovolcano · 2,857 m Last eruption 2023
- Pavlof Stratovolcano · 2,493 m Last eruption 2022
- Mauna Loa Shield · 4,170 m Last eruption 2022
Frequently asked questions
What tectonic plate is the United States on?
The United States spans 2 tectonic plates: the North American Plate (99%) and the Pacific Plate (1.1%).
Is the United States on a plate boundary?
3 plate boundaries run through or along the United States: the Pacific-Juan de Fuca boundary (divergent, about 5.6 cm/yr), the Juan de Fuca-North American boundary (convergent, about 4.0 cm/yr) and the North American-Pacific boundary (convergent, about 5.6 cm/yr).
Does the United States get earthquakes?
The United States is one of the most earthquake-prone countries on Earth. The USGS catalog lists 320 earthquakes of magnitude 6.5 or more in or just off the United States since 1900, which ranks it 3 of 213 countries. The largest was the M9.2 Prince William Sound, Alaska Earthquake in 1964.
Are there volcanoes in the United States?
The Smithsonian Global Volcanism Program lists 135 volcanoes active in the last 12,000 years in the United States, the most of any country.