QuakeIndex

Fault · Washington

Langley Hill fault

35 kmlong (22 mi), as mapped
< 0.2 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
3quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move less than 0.2 mm a year — under 2 cm a century. Slow faults can still produce large earthquakes, just rarely.

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

This week vs. its last ten years

Too quiet to rank: fewer than half a year's worth of weeks with any M1.5+ quake within 5 km, in ten years. A single quake here would read as "unusual", so we do not score it.

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

Cascadia megathrustCascadia fold and fault beltOlympia structureNorth Ninitat faultSouthern Whidbey Island faultSaddle Hill faultGrays Harbor faultSaddle Mountain faults
The Langley Hill fault as mapped at the surface (glowing), with the other mapped faults nearby, 3 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), . 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.

Most recent near it

  1. M 2.6 8 km NW of Hoquiam, Washington
    2023-10-02 · 10 km from the trace
  2. M 2.5 10 km NNW of Hoquiam, Washington
    2020-12-06 · 10 km from the trace
  3. M 3.4 6 km E of Copalis Beach, Washington
    2019-05-21 · 1 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.