Earthquake · automatic estimate, may change
M 1.9md
Earthquake near Antioch, CA
No earthquake was likely felt in Antioch in the 24 hours to 4:01 pm PST (00:01 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 1.9 earthquake was recorded 6 km (4 mi) southwest of Antioch, CA, at 4:23 pm PDT on 15 September 2026 (23:23 UTC), 14 km deep. The magnitude and location are an automatic first estimate and may change.
USGS: 6 km SW of Antioch, CA
5 km (3 mi) WSW of Antioch, CA
- When
- 4:23 pm PDT on 15 September 2026 ()
- Where
- 6 km (4 mi) southwest of Antioch, CA · earthquakes near Antioch
- Magnitude
- M 1.9 (md)
- Depth
- 14 km below the surface
- Felt
- no reports yet
- Nearest
- Contra Costa County, 10 km WSW
- Nearest mapped fault
- Greenville fault, 6 km from its surface trace — near is not the same as on
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 58 days ago
Earthquake alerts for Antioch, CA
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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 4 km (2 mi) from the epicentre. In Antioch, 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.
Earthquakes near other towns within 30 km: Clayton, Pittsburg, Bay Point, Oakley, Brentwood, Concord.
How big was it?
This earthquake released about 20 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 760,000× the energy of this one
- Magna, Utah 2020 M 5.7 540,000× the energy of this one
- Around the size people start to feel M 3.0 48× the energy of this one
- This earthquake M 1.9 about 20 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 7,400 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 · 49 km NW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 15 km SSE of this epicentre
- 5.4 South of Elmira, California · 38 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 · 18 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 37.9607, -121.8517. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 10 km (6 mi) | WSW | earthquakes near Contra Costa County |
| Solano County, CA | 35 km (22 mi) | NNW | earthquakes near Solano County |
| Alameda County, CA | 35 km (22 mi) | S | earthquakes near Alameda County |
| San Joaquin County, CA | 51 km (32 mi) | E | earthquakes near San Joaquin County |
| Sacramento County, CA | 70 km (44 mi) | NE | earthquakes near Sacramento County |
| Napa County, CA | 74 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
57 earthquakes have been recorded within 50 km since this one.
- 1.6 3 km E of Berkeley, CA
- 2.6 3 km ESE of Berkeley, CA
- 2.1 3 km W of Concord, CA
- 1.3 2 km SSE of Diablo, CA
- 1.3 1 km NE of Diablo, CA
- 2.1 0 km WSW of Diablo, CA
- 1.6 0 km WNW of Diablo, CA
- 1.4 0 km NE of Diablo, CA
- 1.6 0 km NW of Diablo, CA
- 1.4 12 km SE of Livermore, CA
- 2.1 12 km SE of Livermore, CA
- 1.1 2 km SSW of Alamo, CA
- 2.0 7 km ENE of Vallejo, CA
- 1.0 6 km E of Oakland, CA
- 1.3 5 km SSW of Pittsburg, 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.