U.S. state profile · USGS ComCat
Earthquakes in Washington
Washington has catalogued 17 M4+ earthquakes since 2005 (ranked 18th of 39 U.S. states), with the strongest reaching magnitude M6.8.
Washington ranks 18th 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 5 significant M6+ earthquakes since 1900. Below: the full M6+ event history, magnitude and depth profile, and yearly trend.
- 17
- M4+ events (since 2005)
- 5
- Major M6+ (since 1900)
- M6.8
- Strongest
- ~1
- M4+ per year
The verdict
Washington is moderately seismically active, above the global median, with 17 M4+ earthquakes logged since 2005 and 5 major M6+ events since 1900, the strongest reaching magnitude 6.8.
- 1909
- busiest year (1 major events)
- 44 km
- average recorded event depth
- 100%
- of events are shallow (<70 km, the most damaging kind)
Average catalogued magnitude is 4.3 - most events are moderate tremors felt but rarely damaging. On the M4+ activity ladder American Samoa sits immediately above at 24 events and Wyoming sits immediately below at 13.
ComCat magnitude tape
Event tape WA · Washington M4+ · 18th/39
Washington · 17 M4+ · max M6.8 · 5 M6+
- BUSY 17
- SHAL 18th/39
- PCT M6.8
- VS-PEER 5
- COMCAT near American Samoa
- TAPE 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 →
Observed impact record
What ComCat observed after earthquakes in Washington
USGS recorded Modified Mercalli Intensity (MMI) for 3 events in this catalogued record; their average observed intensity was MMI 7.0. These are only events with an observation, not an estimate of future shaking or a safety rating.
- MMI observations
- 3
- Average observed MMI
- 7.0
- PAGER alerts / tsunami flags
- 0 / 0
Source: USGS Comprehensive Earthquake Catalog (ComCat) GeoJSON impact fields. Missing MMI, alert, and tsunami values remain unreported rather than being treated as zero.
Where Washington sits in the catalog
Rank 18th of 39 tracked U.S. states and territories (54th percentile by M4+ count since 2005). On the M4+ activity ladder American Samoa sits immediately above at 24 events and Wyoming sits immediately below at 13.
- American Samoa - next more active (24 M4+)
- Wyoming - next less active (13 M4+)
Washington's M4+ count vs. every tracked state
Total catalogued M4+ events since 2005, USGS ComCat
17 Top 46% higher than 54% 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 Washington by year
Count of significant (magnitude 6.0+) events catalogued each year
- 1909
1909: 1 major (M6+) events
1
- 1939
1939: 1 major (M6+) events
1
- 1949
1949: 1 major (M6+) events
1
- 1965
1965: 1 major (M6+) events
1
- 2001
2001: 1 major (M6+) events
1
What this shows Washington's most active year for major earthquakes was 1909 (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 5 significant (M6+) earthquakes on record for Washington.
M6.0–6.9
5
100.0%
Depth of major earthquakes
Hypocentral depth of the 5 M6+ events, shallow quakes shake the surface hardest. Average depth: 44 km.
Shallow (<70 km)
5
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. Washington's latest M4+ catalog entry is dated Mar 3, 2025. For the national PGA design-basis tiers, see the seismic risk maps guide or the USGS National Seismic Hazard Model.
Strongest earthquakes in Washington
The 5 most powerful events on record (USGS, since 1900).
| Mag | Location | Depth | Date |
|---|---|---|---|
| 6.8 | 7 km SSE of Longbranch, Washington | 51.8 km | Feb 28, 2001 |
| 6.7 | 1 km ENE of Dash Point, Washington | 64.2 km | Apr 29, 1965 |
| 6.7 | 4 km WNW of Roy, Washington | 50.0 km | Apr 13, 1949 |
| 6.1 | Puget Sound region, Washington | 55.0 km | Nov 13, 1939 |
| 6.0 | San Juan Islands, Washington | 0.0 km | Jan 11, 1909 |
Significant earthquake record (5 events)
Every catalogued magnitude-6.0-and-above earthquake in Washington since 1900, most recent first.
| Mag | Location | Depth | Date |
|---|---|---|---|
| 6.8 | 7 km SSE of Longbranch, Washington | 51.8 km | Feb 28, 2001 |
| 6.7 | 1 km ENE of Dash Point, Washington | 64.2 km | Apr 29, 1965 |
| 6.7 | 4 km WNW of Roy, Washington | 50.0 km | Apr 13, 1949 |
| 6.1 | Puget Sound region, Washington | 55.0 km | Nov 13, 1939 |
| 6.0 | San Juan Islands, Washington | 0.0 km | Jan 11, 1909 |
Peak-magnitude sample from the same roster
A Washington-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 Washington-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.