QuakeIndex

Fault · Arizona, Utah

Washington fault

72 kmlong (45 mi), as mapped
< 0.2 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
16quakes 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.

The largest earthquake recorded near it was M 6.3 in 1902 (Near Pine Valley, Utah) — about 100,000 times the energy of an M3.0, the size people start to feel. It released about 49 kilotons of TNT.

USGS maps it as 3 sections: Mokaac section, Sullivan Draw section, northern section.

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: 0–0.

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

Sevier/Toroweap faultHurricane fault M 6.3 · 1902 · Near Pine Valley, Utah
The Washington fault as mapped at the surface (glowing), with the other mapped faults nearby, 16 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 6.3 Near Pine Valley, Utah
    November 17, 1902 · epicentre 25 km from the trace
  2. M 4.4 45 km ESE of Littlefield, Arizona
    September 19, 2022 · epicentre 6 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 2.7 56 km SE of Scenic, Arizona
    2025-03-11 · 3 km from the trace
  2. M 2.9 10 km SSE of Washington, Utah
    2024-07-24 · 1 km from the trace
  3. M 2.6 56 km SE of Scenic, Arizona
    2023-05-14 · 5 km from the trace
  4. M 4.4 45 km ESE of Littlefield, Arizona
    2022-09-19 · 6 km from the trace
  5. M 2.5 16 km SSE of Saint George, Utah
    2020-02-16 · 2 km from the trace
  6. M 2.8 16 km SSE of Saint George, Utah
    2019-08-15 · 2 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.