U.S. state profile · USGS ComCat
Earthquakes in American Samoa
American Samoa has catalogued 24 M4+ earthquakes since 2005 (ranked 17th of 39 U.S. states), with the strongest reaching magnitude M6.4.
American Samoa ranks 17th of 39 U.S. states and territories by catalogued seismic activity - a state with limited seismic activity, averaging about 1 M4+ events a year alongside 4 significant M6+ earthquakes since 1900. Below: the full M6+ event history, magnitude and depth profile, and yearly trend.
- 24
- M4+ events (since 2005)
- 4
- Major M6+ (since 1900)
- M6.4
- Strongest
- ~1
- M4+ per year
The verdict
American Samoa is moderately seismically active, above the global median, with 24 M4+ earthquakes logged since 2005 and 4 major M6+ events since 1900, the strongest reaching magnitude 6.4.
- 1917
- busiest year (1 major events)
- 14 km
- average recorded event depth
- 100%
- of events are shallow (<70 km, the most damaging kind)
Average catalogued magnitude is 4.7 - most events are moderate tremors felt but rarely damaging. On the M4+ activity ladder Utah sits immediately above at 25 events and Washington sits immediately below at 17.
ComCat magnitude tape
Event tape AS · American Samoa M4+ · 17th/39
American Samoa · 24 M4+ · max M6.4 · 4 M6+
- BAND 24
- STRIP 17th/39
- BOOK M6.4
- RANK 4
- MAX near Utah
- M6 100% shallow
Stamps derive from this jurisdiction's USGS ComCat row (M4+ book, rank, peak magnitude, M6+ record, ladder neighbour, depth/peak year), not a hazard forecast. PlainQuake is informational only - not professional advice and not a substitute for official USGS guidance. See our disclaimer. Verify with USGS ComCat → · Read with methodology → · How earthquakes are measured → · Most active U.S. regions → · All state catalog rows → · States ranked →
Where American Samoa sits in the catalog
Rank 17th of 39 tracked U.S. states and territories (56th percentile by M4+ count since 2005). On the M4+ activity ladder Utah sits immediately above at 25 events and Washington sits immediately below at 17.
- Utah - next more active (25 M4+)
- Washington - next less active (17 M4+)
American Samoa's M4+ count vs. every tracked state
Total catalogued M4+ events since 2005, USGS ComCat
24 Top 44% higher than 56% of 39 states
Each bar is a 100-wide band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source USGS Comprehensive Earthquake Catalog (ComCat) · 2005-present
Major (M6+) earthquakes in American Samoa by year
Count of significant (magnitude 6.0+) events catalogued each year
- 1917
1917: 1 major (M6+) events
1
- 1925
1925: 1 major (M6+) events
1
- 1944
1944: 1 major (M6+) events
1
- 2003
2003: 1 major (M6+) events
1
What this shows American Samoa's most active year for major earthquakes was 1917 (1 M6+ events). Major-quake counts track the episodic release of tectonic stress, not a smooth trend.
Magnitude distribution of major events
Breakdown of the 4 significant (M6+) earthquakes on record for American Samoa.
M6.0–6.9
4
100.0%
Depth of major earthquakes
Hypocentral depth of the 4 M6+ events, shallow quakes shake the surface hardest. Average depth: 14 km.
Shallow (<70 km)
4
100% of events
Intermediate (70–300 km)
0
0.0% of events
Deep (>300 km)
0
0.0% of events
Seismic hazard context
Catalogued counts on this page are history, not a building-code hazard map. American Samoa's latest M4+ catalog entry is dated Oct 30, 2025. For the national PGA design-basis tiers, see the seismic risk maps guide or the USGS National Seismic Hazard Model.
Strongest earthquakes in American Samoa
The 4 most powerful events on record (USGS, since 1900).
| Mag | Location | Depth | Date |
|---|---|---|---|
| 6.4 | 188 km SW of Vailoatai, American Samoa | 15.0 km | Oct 11, 1944 |
| 6.3 | 171 km S of Vailoatai, American Samoa | 15.0 km | Jun 19, 1925 |
| 6.2 | 246 km SSE of Vaitogi, American Samoa | 10.0 km | Oct 7, 2003 |
| 6.2 | 211 km SSW of Vailoatai, American Samoa | 15.0 km | Jun 28, 1917 |
Significant earthquake record (4 events)
Every catalogued magnitude-6.0-and-above earthquake in American Samoa since 1900, most recent first.
| Mag | Location | Depth | Date |
|---|---|---|---|
| 6.2 | 246 km SSE of Vaitogi, American Samoa | 10.0 km | Oct 7, 2003 |
| 6.4 | 188 km SW of Vailoatai, American Samoa | 15.0 km | Oct 11, 1944 |
| 6.3 | 171 km S of Vailoatai, American Samoa | 15.0 km | Jun 19, 1925 |
| 6.2 | 211 km SSW of Vailoatai, American Samoa | 15.0 km | Jun 28, 1917 |
Peak-magnitude sample from the same roster
A American Samoa-keyed shuffle of states with a recorded max magnitude. Layout order flips by state so sibling pages do not open the same block first.
Other states in this catalog sample
A second American Samoa-keyed shuffle of the full 38-state roster (not ABS-gap nearest neighbors).
According to the US Geological Survey Earthquake Hazards Program, PlainQuake's figures are rendered directly from 317,293 recorded M4+ earthquakes and 14,444 significant M6+ events (USGS ComCat, 2005-present) -- no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-08-26.