QuakeIndex

Fault · Washington

Seattle fault

69 kmlong (43 mi), as mapped
0.2–1 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
37quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 0.2 to 1 mm a year — 2 to 10 cm every century.

Its most recent surface rupture is younger than 15,000 years.

The largest earthquake recorded near it was M 6.7 in 1965 (1 km ENE of Dash Point, Washington) — about 350,000 times the energy of an M3.0, the size people start to feel. It released about 170 kilotons of TNT.

This week vs. its last ten years

0/100

quiet

0 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 0% of weeks since 2016. A normal week: 0–1.

Computed from the USGS catalogue · a description of the past, not a forecast · method

Olympia structureSouthern Whidbey Island faultRattlesnake Mountain faultLake Creek-Boundary Creek faultTacoma faultCherry Creek faultSaddle Mountain faults M 6.7 · 1965 · 1 km ENE of Dash Point, Washington M 6.1 · 1939 · Puget Sound region, Washington
The Seattle fault as mapped at the surface (glowing), with the other mapped faults nearby, 37 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), and the epicentres of the large historic earthquakes recorded near it (rings). Traces: USGS Quaternary Fault and Fold Database. Historic epicentres are estimates.

Every year since 2016

Earthquakes of M2.5+ with an epicentre within 10 km of the mapped trace. Near is not the same as on: some will have slipped on neighbouring faults.

The big ones recorded near it

  1. M 6.7 1 km ENE of Dash Point, Washington
    April 29, 1965 · epicentre 22 km from the trace
  2. M 6.1 Puget Sound region, Washington
    November 13, 1939 · epicentre 18 km from the trace

Before 1973 from the USGS ComCat historical catalogue (within 25 km; epicentres of old earthquakes are estimates). Since 2016, M4+ within 10 km.

Most recent near it

  1. M 2.6 1 km ENE of Enetai, Washington
    2026-01-25 · 1 km from the trace
  2. M 3.0 2 km NNW of Ames Lake, Washington
    2026-01-22 · 7 km from the trace
  3. M 2.8 5 km W of Gorst, Washington
    2025-12-25 · 4 km from the trace
  4. M 2.9 0 km NW of Keyport, Washington
    2025-08-02 · 10 km from the trace
  5. M 2.8 3 km NE of Fall City, Washington
    2025-07-31 · 7 km from the trace
  6. M 2.8 0 km ENE of Tracyton, Washington
    2025-02-27 · 0 km from the trace

Neighbouring faults

Fault trace, slip rate and age: USGS Quaternary Fault and Fold Database (public domain), simplified for the web. Earthquakes: USGS ComCat. QuakeIndex does not forecast earthquakes; a fault's history describes the past. For early warning use ShakeAlert.