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.
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
How American Samoa compares to its nearest peers
American Samoa ranks in the 56th percentile for M4+ frequency among all 39 tracked U.S. states and territories. Plotted here against its 20 nearest-ranked peers by how OFTEN they shake (M4+ count) against how HARD the strongest one ever hit (max recorded magnitude).
Read the chart (all 21 values)
| State | M4+ events | Strongest magnitude |
|---|---|---|
| U.S. Virgin Islands | 221 | M6.1 |
| Hawaii | 204 | M6.9 |
| Nevada | 170 | M6.5 |
| Oklahoma | 97 | M5.8 |
| Idaho | 73 | M6.5 |
| Georgia | 67 | M6.0 |
| Texas | 52 | M5.4 |
| New Mexico | 37 | M5.4 |
| Montana | 28 | M5.8 |
| Utah | 25 | M5.7 |
| American Samoa (this page) | 24 | M5.8 |
| Washington | 17 | M4.7 |
| Wyoming | 13 | M4.8 |
| Colorado | 12 | M5.3 |
| Kansas | 12 | M4.9 |
| Arizona | 7 | M5.3 |
| Arkansas | 5 | M4.7 |
| Louisiana | 5 | M5.3 |
| Virginia | 5 | M5.8 |
| Illinois | 3 | M5.2 |
| Tennessee | 3 | M4.4 |
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).
Frequently asked questions
How many earthquakes hit American Samoa? ▼
What was the largest earthquake in American Samoa? ▼
How does American Samoa rank for earthquakes? ▼
Where does this data come from? ▼
Understand the data
About American Samoa's figures
24 M4+ events since 2005 · strongest M6.4 · average M4.7 · 4 M6+ significant events since 1900 · latest M4+ catalog stamp Oct 30, 2025. Computed from the USGS Comprehensive Earthquake Catalog (ComCat); state assignment uses USGS place-name geocoding. See the methodology and USGS ComCat.
Disclaimer: PlainQuake is informational only, not an emergency service or engineering advice. See our full disclaimer.
What American Samoa's numbers mean
American Samoa ranks 17th of 39 U.S. states and territories - a state with limited seismic activity.
- See American Samoa's computed risk level alongside every other state, using the same USGS-derived methodology. Open the risk calculator
- 100% of American Samoa's catalogued major earthquakes are shallow (under 70km) - shallow events generally produce stronger surface shaking than deep ones of the same magnitude. How depth affects shaking
- Compare American Samoa against every other U.S. state by count and maximum magnitude. See the full state ranking
Figures reflect the USGS ComCat catalog (M4+ since 2005, M6+ significant events since 1900) - not a real-time hazard assessment. For official guidance, see the USGS Earthquake Hazards Program.
According to the US Geological Survey Earthquake Hazards Program, PlainQuake's figures are rendered directly from 315,341 recorded M4+ earthquakes and 14,428 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 2026-07-19.