QuakeIndex

Fault · California

San Diego Trough fault

121 kmlong (75 mi), as mapped
1–5 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
30quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 1 to 5 mm a year — 10 to 50 cm (4 to 20 inches) every century.

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

The largest earthquake recorded near it was M 6.3 in 1800 (Gulf of Santa Catalina, California) — about 89,000 times the energy of an M3.0, the size people start to feel. It released about 43 kilotons of TNT.

This week vs. its last ten years

87/100

elevated

1 quake of M1.5+ within 5 km of the trace in the last 7 days — busier than 87% 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 faultElsinore faultSan Jacinto faultNewport-Inglewood-Rose Canyon faultSan Clemente faultCatalina faultPalos Verdes faultSan Pedro Basin faultSan Onofre faultSan Joaquin Hills thrustCarlsbad faultCarslbad Ridge fault M 6.3 · 1800 · Gulf of Santa Catalina, California
The San Diego Trough fault as mapped at the surface (glowing), with the other mapped faults nearby, 30 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 Gulf of Santa Catalina, California
    November 22, 1800 · epicentre on 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 3.3 26 km ESE of Avalon, CA
    2026-09-12 · 1 km from the trace
  2. M 3.0 26 km ESE of Avalon, CA
    2026-09-12 · 0 km from the trace
  3. M 2.5 26 km ESE of Avalon, CA
    2026-09-12 · 1 km from the trace
  4. M 3.2 13 km NNE of Avalon, CA
    2026-07-06 · 8 km from the trace
  5. M 2.7 42 km NE of San Clemente Is. (SE tip), CA
    2024-11-14 · 7 km from the trace
  6. M 3.0 45 km NE of San Clemente Is. (SE tip), CA
    2024-10-28 · 3 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.