QuakeIndex

Fault · California

Imperial fault

46 kmlong (29 mi), as mapped
> 5 mm/yrhow fast it slips
last 150 yearssince it last broke the surface
96quakes 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

82/100

elevated

2 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 82% of weeks since 2016. A normal week: 0–1.

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

San Andreas faultElsinore faultSan Jacinto faultAlgodones faultBrawley Seismic ZoneExtra faultYuha Well Fault ZoneHot Springs faultYuha Basin faults M 6.9 · 1940 · The 1940 Imperial Valley, 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 Imperial fault as mapped at the surface (glowing), with the other mapped faults nearby, 96 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 9 km from the trace
  2. M 6.3 The 1906 Imperial Valley, California Earthquake
    April 19, 1906 · epicentre 11 km from the trace
  3. M 6.0 The 1915 Imperial Valley, California Earthquakes (First Major Event)
    June 23, 1915 · epicentre 3 km from the trace
  4. M 4.6 2 km NNW of El Centro, CA
    February 12, 2024 · epicentre 9 km from the trace
  5. M 4.1 7 km WSW of Holtville, CA
    January 15, 2026 · 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 2.5 8 km W of Holtville, CA
    2026-05-19 · 1 km from the trace
  2. M 3.0 7 km NE of Calexico, CA
    2026-03-04 · 7 km from the trace
  3. M 4.1 7 km WSW of Holtville, CA
    2026-01-15 · 0 km from the trace
  4. M 3.4 7 km WSW of Holtville, CA
    2026-01-15 · 0 km from the trace
  5. M 2.8 7 km SW of Holtville, CA
    2025-01-08 · 1 km from the trace
  6. M 3.1 1 km ESE of El Centro, CA
    2025-01-06 · 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.