Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Clayton, CA
No earthquake was likely felt in Clayton in the 24 hours to 11:02 pm PST (07:02 UTC). The last one was M 2.1, 11 km (7 mi) W, at 4:05 am PST on 8 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Clayton
This page: a magnitude 1.8 earthquake was recorded 5 km (3 mi) southwest of Clayton, CA, at 8:08 am PST on 19 December 2024 (16:08 UTC), 12 km deep.
USGS: 5 km SW of Clayton, CA
6 km (3 mi) E of Walnut Creek, CA · 41 km (26 mi) ENE of San Francisco, CA
- When
- 8:08 am PST on 19 December 2024 ()
- Where
- 5 km (3 mi) southwest of Clayton, CA · earthquakes near Clayton
- Magnitude
- M 1.8 (md)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Contra Costa County, 3 km ENE
- Nearest mapped fault
- Greenville 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 680 days ago
Earthquake alerts for Clayton, 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 5 km (3 mi) from the epicentre. In Clayton, 5 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: Waldon, Contra Costa Centre, Walnut Creek, Alamo, Diablo, Pleasant Hill.
How big was it?
This earthquake released about 14 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 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 760,000× the energy of this one
- Around the size people start to feel M 3.0 68× the energy of this one
- This earthquake M 1.8 about 14 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 10,000 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 · 45 km NW of this epicentre
- 5.8 The 1980 Livermore, California Earthquake · 20 km ESE of this epicentre
- 5.4 South of Elmira, California · 44 km N of this epicentre
- 5.4 9 km NE of Livermore, California · 30 km SE of this epicentre
- 5.1 11 km E of Blackhawk, California · 21 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 37.9063, -121.9770. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Contra Costa County, CA | 3 km (2 mi) | ENE | earthquakes near Contra Costa County |
| Alameda County, CA | 29 km (18 mi) | S | earthquakes near Alameda County |
| Solano County, CA | 40 km (25 mi) | N | earthquakes near Solano County |
| San Joaquin County, CA | 62 km (38 mi) | E | earthquakes near San Joaquin County |
| San Mateo County, CA | 65 km (40 mi) | SSW | earthquakes near San Mateo County |
| Marin County, CA | 69 km (43 mi) | WNW | earthquakes near Marin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 1.6 5 km E of Vallejo, CA
- 2.1 12 km NNE of Bay Point, CA
- 2.3 0 km SSW of Concord, CA
- 1.7 4 km W of Alamo, CA
- 2.5 4 km W of Alamo, CA
- 2.5 4 km W of Alamo, CA
- 1.7 13 km NNE of Pittsburg, CA
- 1.6 1 km S of Pacheco, CA
- 1.7 0 km NNE of East Richmond Heights, CA
- 2.1 12 km ENE of Milpitas, CA
- 1.5 7 km E of Vallejo, CA
- 1.8 3 km ESE of Pacheco, CA
- 1.8 6 km SW of Clayton, CA
- 1.5 4 km SE of Oakland, CA
- 1.6 3 km SW of Clayton, 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.