QuakeIndex

Fault · California

Brawley Seismic Zone

68 kmlong (42 mi), as mapped
> 5 mm/yrhow fast it slips
last 150 yearssince it last broke the surface
751quakes of M2.5+ within 10 km since 2016

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 6.9 in 1940 (The 1940 Imperial Valley, California Earthquake) — about 710,000 times the energy of an M3.0, the size people start to feel. It released about 340 kilotons of TNT.

This week vs. its last ten years

56/100

typical

3 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 56% of weeks since 2016. A normal week: 1–5.

Computed from the USGS catalogue · a description of the past, not a forecast · method

San Andreas faultElsinore faultSan Jacinto faultAlgodones faultImperial faultExtra faultMecca Hills faultHidden Spring faultIndio Hills Fault ZoneCoachella Fan Fault ZoneYuha Well Fault ZoneSkeleton Canyon faultHot Springs faultYuha Basin faults M 6.9 · 1940 · The 1940 Imperial Valley, California Earthquake M 6.6 · 1942 · The 1942 Fish Creek Mountains, California Earthquake M 6.3 · 1906 · The 1906 Imperial Valley, California Earthquake M 6.0 · 1915 · The 1915 Imperial Valley, California Earthquakes (First Major Event)
The Brawley Seismic Zone as mapped at the surface (glowing), with the other mapped faults nearby, 400 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 6.9 The 1940 Imperial Valley, California Earthquake
    May 19, 1940 · epicentre 10 km from the trace
  2. M 6.6 The 1942 Fish Creek Mountains, California Earthquake
    October 21, 1942 · epicentre 21 km from the trace
  3. M 6.3 The 1906 Imperial Valley, California Earthquake
    April 19, 1906 · epicentre 2 km from the trace
  4. M 6.0 The 1915 Imperial Valley, California Earthquakes (First Major Event)
    June 23, 1915 · epicentre 9 km from the trace
  5. M 5.3 11km W of Calipatria, CA
    June 5, 2021 · epicentre 2 km from the trace
  6. M 4.9 4km NE of Westmorland, CA
    October 1, 2020 · epicentre 1 km from the trace
  7. M 4.8 3 km NNW of El Centro, CA
    February 12, 2024 · epicentre 10 km from the trace
  8. M 4.7 3 km WSW of Brawley, CA
    May 10, 2026 · epicentre 1 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 11 km SW of Niland, CA
    2026-08-11 · 2 km from the trace
  2. M 3.0 10 km SW of Niland, CA
    2026-07-25 · 2 km from the trace
  3. M 3.2 7 km S of Brawley, CA
    2026-07-23 · 0 km from the trace
  4. M 2.7 8 km S of Brawley, CA
    2026-07-23 · 0 km from the trace
  5. M 2.8 8 km S of Brawley, CA
    2026-07-23 · 0 km from the trace
  6. M 3.3 8 km NNE of Imperial, CA
    2026-07-23 · 0 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.