QuakeIndex

Fault · California

Long Valley fault

28 kmlong (17 mi), as mapped
not measuredhow fast it slips
< 15,000 yearssince it last broke the surface
34quakes of M2.5+ within 10 km since 2016

In plain English

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

The largest earthquake recorded near it was M 6.8 in 1872 (Near Round Valley, California) — about 500,000 times the energy of an M3.0, the size people start to feel. It released about 240 kilotons of TNT.

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

San Andreas faultSouthern Sierra Nevada faultOwens Valley faultWassuk Range faultWhite Mountains faultFish Lake Valley faultBenton Spring faultHuntoon Valley fault systemEmigrant Peak faultRound Valley faultSilver Lake faultHilton Creek faultDeep Springs faultFish Slough faultHartley Springs faultMono Lake faultRobinson Creek faultMcAfee Canyon fault M 6.8 · 1872 · Near Round Valley, California M 6.0 · 1941 · Mammoth Lakes area, California M 6.0 · 1941 · Mammoth Lakes area, California
The Long Valley fault as mapped at the surface (glowing), with the other mapped faults nearby, 34 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 6.8 Near Round Valley, California
    April 11, 1872 · epicentre 13 km from the trace
  2. M 6.0 Mammoth Lakes area, California
    September 14, 1941 · epicentre 5 km from the trace
  3. M 6.0 Mammoth Lakes area, California
    September 14, 1941 · epicentre 5 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 2.9 7 km WNW of Round Valley, CA
    2026-05-27 · 8 km from the trace
  2. M 2.5 8 km NE of Round Valley, CA
    2025-01-28 · 9 km from the trace
  3. M 2.6 10 km S of Toms Place, CA
    2023-10-03 · 7 km from the trace
  4. M 2.5 6km NW of Round Valley, CA
    2023-06-18 · 8 km from the trace
  5. M 2.6 6km NW of Round Valley, CA
    2023-06-09 · 8 km from the trace
  6. M 2.5 9km SW of Toms Place, CA
    2023-04-05 · 10 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.