Micronesia
What tectonic plate is Guam on?
Guam sits entirely on the Mariana Plate.
- Plates
- 1
- M6.5+ quakes since 1900
- 12
- Holocene volcanoes
- 0
- Land area
- 482 km²
Plates under Guam
Share of Guam's land area on each plate (PB2002 model, Natural Earth outlines).
Plate boundaries
2 plate boundaries run through or along Guam: the Mariana-Pacific boundary (convergent, about 6.3 cm/yr) and the Philippine Sea-Mariana boundary (divergent, about 3.1 cm/yr).
- Mariana and Pacific: convergent, 6.3 cm/yr
- Philippine Sea and Mariana: divergent, 3.1 cm/yr
The fastest of these is the Mariana-Pacific boundary, where the plates move about 6.3 cm/yr relative to each other. That is faster than fingernails grow.
Earthquakes in Guam
Guam has frequent large earthquakes: 12 of magnitude 6.5 or more struck in or just off the country since 1900 (rank 40 of 213).
| Earthquake | Magnitude | Year | Depth | Plate |
|---|---|---|---|---|
| 32 km S of Inarajan Village, Guam | M7.8 | 1993 | 59 km | Mariana |
| 265 km S of Merizo Village, Guam | M7.2 | 1931 | 15 km | Pacific |
| 261 km S of Merizo Village, Guam | M7.1 | 1917 | 15 km | Pacific |
| 20 km SSW of Merizo Village, Guam | M7.1 | 2002 | 86 km | Mariana |
| 98 km SSE of Inarajan Village, Guam | M7.0 | 1909 | 15 km | Mariana |
| 32 km NNE of Yigo Village, Guam | M7.0 | 1912 | 180 km | Mariana |
Volcanoes in Guam
Guam has no volcanoes that have erupted in the last 12,000 years, according to the Smithsonian Global Volcanism Program.
Frequently asked questions
What tectonic plate is Guam on?
Guam sits entirely on the Mariana Plate.
Is Guam on a plate boundary?
2 plate boundaries run through or along Guam: the Mariana-Pacific boundary (convergent, about 6.3 cm/yr) and the Philippine Sea-Mariana boundary (divergent, about 3.1 cm/yr).
Does Guam get earthquakes?
Guam has frequent large earthquakes: 12 of magnitude 6.5 or more struck in or just off the country since 1900 (rank 40 of 213). The largest was the M7.8 32 km S of Inarajan Village, Guam in 1993.
Are there volcanoes in Guam?
Guam has no volcanoes that have erupted in the last 12,000 years, according to the Smithsonian Global Volcanism Program.