Fault · California
San Jacinto 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 7.5 in 1812 (Northwest of San Bernardino, California) — about 5,600,000 times the energy of an M3.0, the size people start to feel. It released about 2.7 megatons of TNT.
USGS maps it as 7 sections: Anza section, Borrego Mountain section, Coyote Creek section, San Bernardino Valley section, San Jacinto Valley section, Superstition Hills section, Superstition Mountain section.
This week vs. its last ten years
57/100
typical
8 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 57% of weeks since 2016. A normal week: 4–10.
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 7.5 Northwest of San Bernardino, California
December 8, 1812 · epicentre 11 km from the trace - M 6.8 Northeastern San Diego County, California
February 9, 1890 · epicentre 2 km from the trace - M 6.7 The 1899 San Jacinto, California Earthquake
December 25, 1899 · epicentre 9 km from the trace - M 6.7 The 1918 San Jacinto, California Earthquake
April 21, 1918 · epicentre 6 km from the trace - M 6.6 The 1942 Fish Creek Mountains, California Earthquake
October 21, 1942 · epicentre 2 km from the trace - M 6.6 The 1968 Borrego Mountain, California Earthquake
April 9, 1968 · epicentre 2 km from the trace - M 5.2 20km NNW of Borrego Springs, CA
June 10, 2016 · epicentre 1 km from the trace - M 4.9 17km ESE of Anza, CA
April 4, 2020 · 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
- M 2.6 9 km WNW of Anza, CA
2026-09-23 · 8 km from the trace - M 2.9 22 km SSW of La Quinta, CA
2026-08-31 · 1 km from the trace - M 3.1 12 km WSW of Salton City, CA
2026-08-25 · 1 km from the trace - M 3.0 24 km WSW of Westmorland, CA
2026-08-02 · 0 km from the trace - M 3.1 9 km SE of Ocotillo Wells, CA
2026-07-15 · 1 km from the trace - M 2.8 18 km WSW of Westmorland, CA
2026-07-05 · 3 km from the trace
Neighbouring faults
- San Gabriel fault 1 km away
- Crafton Hills fault 3 km away
- San Andreas fault 4 km away
- Sierra Madre fault 4 km away
- Cleghorn fault 6 km away
- San Gorgonio Pass fault 8 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.