QuakeIndex

Fault · California

Concord fault

20 kmlong (12 mi), as mapped
1–5 mm/yrhow fast it slips
last 150 yearssince it last broke the surface
29quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 1 to 5 mm a year — 10 to 50 cm (4 to 20 inches) every century.

It has broken the ground surface within the last 150 years.

The largest earthquake recorded near it was M 4.5 in 2019 (1km SSE of Pleasant Hill, CA) — about 150 times the energy of an M3.0, the size people start to feel. It released about 74 tons of TNT.

USGS maps it as 3 sections: Avon section, Concord section, Ygnacio Valley section.

This week vs. its last ten years

0/100

quiet

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

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

San Andreas faultGreat Valley thrust fault systemSan Gregorio faultFoothills fault systemMaacama faultCalaveras faultHayward faultGreenville faultHunting Creek-Berryessa fault systemRodgers Creek faultMonte Vista-Shannon faultWest Napa faultBennett Valley faultGreen Valley faultAlexander-Redwood Hill faultPleasanton faultCordelia faultSerra faultCorral Hollow-Carnegie faultLas Positas fault
The Concord fault as mapped at the surface (glowing), with the other mapped faults nearby, 29 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.

The big ones recorded near it

  1. M 4.5 1km SSE of Pleasant Hill, CA
    October 15, 2019 · epicentre 5 km from the trace
  2. M 4.1 7km NW of Bay Point, CA
    June 2, 2022 · epicentre 9 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 2.5 2 km SE of Concord, CA
    2026-08-17 · 5 km from the trace
  2. M 2.6 2 km WNW of Concord, CA
    2025-10-30 · 0 km from the trace
  3. M 2.5 2 km NW of Walnut Creek, CA
    2025-07-04 · 7 km from the trace
  4. M 3.1 2 km SW of Concord, CA
    2025-05-30 · 3 km from the trace
  5. M 2.5 5 km W of Pleasant Hill, CA
    2025-02-14 · 8 km from the trace
  6. M 3.5 2 km ENE of Pleasant Hill, CA
    2025-01-12 · 2 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.