Fault · California
San Andreas fault
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.
It has broken the ground surface within the last 150 years.
The largest earthquake recorded near it was M 7.9 in 1857 (The 1857 Fort Tejon, California Earthquake) — about 25,000,000 times the energy of an M3.0, the size people start to feel. It released about 12 megatons of TNT.
USGS maps it as 12 sections: Cholame-Carrizo section, Coachella section, Creeping section, King Range section, Mojave section, North Coast section, Parkfield section, Peninsula section….
This week vs. its last ten years
13/100
quiet
8 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 13% of weeks since 2016. A normal week: 9–15.
Computed from the USGS catalogue · a description of the past, not a forecast · method
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
- M 7.9 The 1857 Fort Tejon, California Earthquake
January 9, 1857 · epicentre 1 km from the trace - M 7.9 The 1906 San Francisco, California Earthquake
April 18, 1906 · epicentre 1 km from the trace - M 7.5 Northwest of San Bernardino, California
December 8, 1812 · epicentre 1 km from the trace - M 7.5 The 1952 Kern County, California Earthquake
July 21, 1952 · epicentre 15 km from the trace - M 7.4 The 1838 San Andreas Fault, California Earthquake
June 25, 1838 · epicentre on the trace - M 6.7 South of Mendocino, California
April 15, 1898 · epicentre 2 km from the trace - M 5.6 6km SSW of Petrolia, CA
June 23, 2019 · epicentre 9 km from the trace - M 4.7 17km SSE of Tres Pinos, CA
October 15, 2019 · 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
- M 2.6 2 km NW of Hollister, CA
2026-09-23 · 8 km from the trace - M 2.6 2 km ENE of Aromas, CA
2026-09-17 · 1 km from the trace - M 2.6 15 km SE of Petrolia, CA
2026-09-03 · 8 km from the trace - M 2.8 4 km NW of Parkfield, CA
2026-08-23 · 0 km from the trace - M 2.6 5 km S of Petrolia, CA
2026-08-14 · 10 km from the trace - M 2.7 5 km NW of Pinnacles, CA
2026-08-11 · 0 km from the trace
Neighbouring faults
- Mattole Canyon fault touching
- San Gregorio fault 1 km away
- Pinto Mountain fault (includes Morongo Valley fault) 1 km away
- San Juan fault 1 km away
- Sargent fault 1 km away
- Crafton Hills fault 1 km away
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.