QuakeIndex

Fault · California

Serra fault

15 kmlong (9 mi), as mapped
not measuredhow fast it slips
< 15,000 yearssince it last broke the surface
18quakes 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 7.9 in 1906 (The 1906 San Francisco, California Earthquake) — about 22,000,000 times the energy of an M3.0, the size people start to feel. It released about 11 megatons of TNT.

This week vs. its last ten years

79/100

elevated

1 quake of M1.5+ within 5 km of the trace in the last 7 days — busier than 79% 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 faultGreat Valley thrust fault systemSan Gregorio faultCalaveras faultHayward faultGreenville faultMonterey Bay- Tularcitos faultZayante-Vergeles faultRodgers Creek faultSargent faultMonte Vista-Shannon faultButano faultWest Napa faultBennett Valley faultGreen Valley faultConcord faultPleasanton faultCordelia faultCorral Hollow-Carnegie faultLas Positas fault M 7.9 · 1906 · The 1906 San Francisco, California Earthquake
The Serra fault as mapped at the surface (glowing), with the other mapped faults nearby, 18 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 7.9 The 1906 San Francisco, California Earthquake
    April 18, 1906 · epicentre 9 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 3 km SSW of San Francisco Zoo, CA
    2026-04-25 · 4 km from the trace
  2. M 2.9 3 km SSW of San Francisco Zoo, CA
    2026-04-25 · 4 km from the trace
  3. M 2.5 3 km SE of Pacifica, CA
    2026-01-14 · 4 km from the trace
  4. M 3.0 3 km SSW of Colma, CA
    2025-11-29 · 2 km from the trace
  5. M 3.5 5 km NW of San Francisco Zoo, CA
    2025-01-10 · 10 km from the trace
  6. M 3.2 5 km WSW of San Francisco Zoo, CA
    2024-02-02 · 7 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.