QuakeIndex

Fault · California

Little Salmon fault

91 kmlong (57 mi), as mapped
> 5 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
68quakes of M2.5+ within 10 km since 2016

In plain English

The two sides grind past each other faster than 5 mm a year — more than half a metre (20 inches) every century.

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

The largest earthquake recorded near it was M 6.5 in 1932 (The 1932 Eureka, California Earthquake) — about 150,000 times the energy of an M3.0, the size people start to feel. It released about 71 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: 0–0.

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

San Andreas faultBartlett Springs fault systemMad River faultBald Mountain-Big Lagoon faultMattole Canyon fault M 6.5 · 1932 · The 1932 Eureka, California Earthquake M 6.3 · 1871 · Northeast of Petrolia, California M 6.3 · 1890 · Near Ferndale, California M 6.0 · 1909 · Near Rio Dell, California
The Little Salmon fault as mapped at the surface (glowing), with the other mapped faults nearby, 68 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 6.5 The 1932 Eureka, California Earthquake
    June 6, 1932 · epicentre 6 km from the trace
  2. M 6.3 Northeast of Petrolia, California
    March 2, 1871 · epicentre 21 km from the trace
  3. M 6.3 Near Ferndale, California
    July 26, 1890 · epicentre 12 km from the trace
  4. M 6.0 Near Rio Dell, California
    October 29, 1909 · epicentre 12 km from the trace
  5. M 4.9 7km WNW of Rio Dell, CA
    December 20, 2022 · epicentre 10 km from the trace
  6. M 4.2 8km E of Hydesville, CA
    December 24, 2022 · epicentre 1 km from the trace
  7. M 4.1 3km SSE of Fortuna, CA
    October 23, 2022 · epicentre 3 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 7 km E of Hydesville, CA
    2026-09-15 · 1 km from the trace
  2. M 2.6 3 km ESE of Fortuna, CA
    2026-07-15 · 0 km from the trace
  3. M 3.0 16 km ENE of Hydesville, CA
    2026-03-21 · 7 km from the trace
  4. M 3.0 6 km SSW of Fortuna, CA
    2025-12-06 · 8 km from the trace
  5. M 2.9 13 km WNW of Bayview, CA
    2025-07-22 · 9 km from the trace
  6. M 2.7 7 km SW of Fortuna, CA
    2025-03-31 · 9 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.