QuakeIndex

Fault · California

Helendale-South Lockhart fault

135 kmlong (84 mi), as mapped
0.2–1 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
46quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 0.2 to 1 mm a year — 2 to 10 cm every century.

Its most recent surface rupture is younger than 15,000 years.

USGS maps it as 3 sections: Helendale section, Northern San Bernardino Mountains section, South Lockhart section.

This week vs. its last ten years

67/100

typical

1 quake of M1.5+ within 5 km of the trace in the last 7 days — busier than 67% 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 faultGarlock faultSan Jacinto faultNewport-Inglewood-Rose Canyon faultSouthern Sierra Nevada faultLenwood-Lockhart faultSan Gabriel faultSierra Madre faultCalico-Hidalgo faultPalos Verdes faultPisgah-Bullion faultCamp Rock-Emerson-Copper Mountain faultPinto Mountain fault (includes Morongo Valley fault)North Frontal thrust systemHarper faultBlackwater faultJohnson Valley faultPuente Hills blind thrust systemLavic Lake faultSan Gorgonio Pass faultManix faultHomestead Valley faultCleghorn faultRaymond faultIndio Hills Fault ZoneBurnt Mountain faultCrafton Hills faultMt. General faultBanning faultEureka Peak faultRed Pass faultLong Canyon faultOld Woman Springs faultRed Hill-Etiwanda Avenue faultBeaumont Plain fault
The Helendale-South Lockhart fault as mapped at the surface (glowing), with the other mapped faults nearby, 46 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), . 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.

Most recent near it

  1. M 2.6 7 km ENE of Big Bear City, CA
    2025-12-19 · 1 km from the trace
  2. M 2.8 3 km N of Big Bear City, CA
    2025-11-01 · 4 km from the trace
  3. M 2.6 7 km N of Big Bear City, CA
    2025-10-05 · 3 km from the trace
  4. M 2.5 7 km N of Big Bear City, CA
    2025-10-05 · 3 km from the trace
  5. M 3.5 7 km N of Big Bear City, CA
    2025-10-05 · 3 km from the trace
  6. M 3.3 7 km N of Big Bear City, CA
    2025-10-05 · 3 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.