Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Antioch, CA
No earthquake was likely felt in Antioch in the 24 hours to 8:31 pm PST (04:31 UTC). The last one was M 3.0, 14 km (9 mi) S, at 6:47 am PDT on 14 September 2026, estimated intensity II (weak) in town; 52 felt reports to USGS. Every earthquake near Antioch
This page: a magnitude 2.5 earthquake was recorded 4 km (2 mi) south-southwest of Antioch, CA, at 1:36 pm PDT on 23 May 2024 (20:36 UTC), 23 km deep. 5 people have reported feeling it to USGS.
USGS: 4 km SW of Antioch, CA
in Antioch, CA
- When
- 1:36 pm PDT on 23 May 2024 ()
- Where
- 4 km (2 mi) south-southwest of Antioch, CA · earthquakes near Antioch
- Magnitude
- M 2.5 (md)
- Depth
- 23 km below the surface
- Felt
- 5 reports · strongest reported intensity III
- Nearest
- Contra Costa County, 13 km WSW
- Nearest mapped fault
- Greenville fault, 9 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 67 days ago
Earthquake alerts for Antioch, CA
Get a notification in this browser when USGS records an earthquake near Antioch, 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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 1 km (1 mi) from the epicentre. In Antioch, 4 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.
Earthquakes near other towns within 30 km: Pittsburg, Clayton, Oakley, Brentwood, Bay Point, Knightsen.
How big was it?
This earthquake released about 190 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 78,000× the energy of this one
- Magna, Utah 2020 M 5.7 55,000× the energy of this one
- Around the size people start to feel M 3.0 4.9× the energy of this one
- This earthquake M 2.5 about 190 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 760 times the energy of this one.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 5.8 The 1980 Livermore, California Earthquake · 16 km SSE of this epicentre
- 5.4 South of Elmira, California · 37 km N of this epicentre
- 5.4 9 km NE of Livermore, California · 27 km SSE of this epicentre
- 5.1 11 km E of Blackhawk, California · 19 km SSE 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 37.9757, -121.8277. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 13 km (8 mi) | WSW | earthquakes near Contra Costa County |
| Solano County, CA | 34 km (21 mi) | NNW | earthquakes near Solano County |
| Alameda County, CA | 37 km (23 mi) | SSW | earthquakes near Alameda County |
| San Joaquin County, CA | 49 km (30 mi) | E | earthquakes near San Joaquin County |
| Sacramento County, CA | 68 km (42 mi) | NE | earthquakes near Sacramento County |
| Napa County, CA | 73 km (46 mi) | NW | earthquakes near Napa County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 1.6 11 km SSE of Suisun City, CA
- 3.1 11 km SSE of Suisun City, CA
- 1.6 9 km S of Elmira, CA
- 2.1 7 km NNW of Bayview-Montalvin, CA
- 1.9 11 km NNE of Bay Point, CA
- 2.4 11 km of Pittsburg, CA
- 1.6 0 km NW of Castro Valley, CA
- 1.7 8 km N of Livermore, CA
- 2.6 7 km SW of Brentwood, CA
- 2.6 10 km E of Blackhawk, CA
- 1.7 5 km E of Vallejo, CA
- 1.8 1 km W of Kensington, CA
- 1.5 3 km ESE of Hayward, CA
- 1.7 3 km E of Hayward, CA
- 2.4 10 km SE of Sunol, 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.