Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Concord, CA
No earthquake was likely felt in Concord in the 24 hours to 8:31 pm PST (04:31 UTC). The last one was M 2.1, 5 km (3 mi) SW, at 4:05 am PST on 8 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Concord
This page: a magnitude 1.8 earthquake was recorded 6 km (4 mi) south-southeast of Concord, CA, at 7:01 am PDT on 19 April 2023 (14:01 UTC), 11 km deep.
USGS: 5km S of Concord, CA
5 km (3 mi) S of Concord, CA · in Walnut Creek, CA
- When
- 7:01 am PDT on 19 April 2023 ()
- Where
- 6 km (4 mi) south-southeast of Concord, CA · earthquakes near Concord
- Magnitude
- M 1.8 (md)
- Depth
- 11 km below the surface
- Felt
- no reports yet
- Nearest
- Contra Costa County, 5 km E
- Nearest mapped fault
- Concord fault, 6 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1301 days ago
Earthquake alerts for Concord, CA
Get a notification in this browser when USGS records an earthquake near Concord, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Concord, 6 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Pleasant Hill 5 km, intensity II · Walnut Creek 5 km, intensity II · Concord 6 km, intensity II · Pacheco 8 km, intensity II · Alamo 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
- Magna, Utah 2020 M 5.7 640,000× the energy of this one
- Around the size people start to feel M 3.0 57× the energy of this one
- This earthquake M 1.8 about 17 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
The largest earthquake within 50 km since 2016 was M 4.5 on 2019-10-15 — about 8,800 times the energy of this one.
Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 41 km NW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 24 km ESE of this epicentre
- 5.4 South of Elmira, California · 43 km NNE of this epicentre
- 5.4 9 km NE of Livermore, California · 33 km SE of this epicentre
- 5.1 11 km E of Blackhawk, California · 24 km ESE of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 37.9260, -122.0128. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 5 km (3 mi) | E | earthquakes near Contra Costa County |
| Alameda County, CA | 32 km (20 mi) | SSE | earthquakes near Alameda County |
| Solano County, CA | 38 km (24 mi) | N | earthquakes near Solano County |
| San Joaquin County, CA | 65 km (40 mi) | E | earthquakes near San Joaquin County |
| San Mateo County, CA | 65 km (40 mi) | SSW | earthquakes near San Mateo County |
| Marin County, CA | 66 km (41 mi) | WNW | earthquakes near Marin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 1.5 6 km ESE of Santa Venetia, CA
- 2.2 3 km N of Vallejo, CA
- 2.7 3 km N of Piedmont, CA
- 1.8 9 km E of Blackhawk, CA
- 1.6 6 km E of Vallejo, CA
- 2.1 3 km NW of Castro Valley, CA
- 2.1 5 km ESE of Oakland, CA
- 1.6 4km E of Berkeley, CA
- 2.0 3km SSW of Port Costa, CA
- 2.1 1km WNW of Kensington, CA
- 1.8 9km SW of Brentwood, CA
- 1.7 2km ENE of Berkeley, CA
- 1.5 1km ENE of Vine Hill, CA
- 1.5 1km S of Green Valley, CA
- 1.8 7km ENE of Vallejo, CA
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.