Earthquake · reviewed by a seismologist
M 2.7md
Earthquake near Vallejo, CA
No earthquake was likely felt in Vallejo in the 24 hours to 3:23 am PST (11:23 UTC). The last one was M 1.8, 8 km (5 mi) ENE, at 11:09 am PST on 4 November 2026, estimated intensity II (weak) in town. Every earthquake near Vallejo
This page: a magnitude 2.7 earthquake was recorded 2 km (1 mi) east of Vallejo, CA, at 12:04 am PDT on 24 September 2021 (07:04 UTC), 11 km deep. 481 people have reported feeling it to USGS.
USGS: 1km SSE of Vallejo, CA
in Vallejo, CA
- When
- 12:04 am PDT on 24 September 2021 ()
- Where
- 2 km (1 mi) east of Vallejo, CA · earthquakes near Vallejo
- Magnitude
- M 2.7 (md)
- Depth
- 11 km below the surface
- Felt
- 481 reports · strongest reported intensity IV
- Nearest
- Solano County, 31 km NE
- Nearest mapped fault
- Green Valley fault, 10 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 814 days ago
Earthquake alerts for Vallejo, CA
Get a notification in this browser when USGS records an earthquake near Vallejo, 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 23 km (14 mi) from the epicentre. In Vallejo, 2 km away, the estimate is intensity III (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: Vallejo 2 km, intensity III · Crockett 6 km, intensity III · Benicia 9 km, intensity II · Hercules 11 km, intensity II · Pinole 12 km, intensity II · Martinez 13 km, intensity II · San Pablo 19 km, intensity II · Pacheco 19 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 350 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 43,000× the energy of this one
- Magna, Utah 2020 M 5.7 31,000× the energy of this one
- Around the size people start to feel M 3.0 2.7× the energy of this one
- This earthquake M 2.7 about 350 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 420 times the energy of this one.
Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:
- 7.9 The 1906 San Francisco, California Earthquake · 48 km SW of this epicentre
- 6.0 The 2014 South Napa, California Earthquake · 14 km NNW of this epicentre
- 5.4 South of Elmira, California · 36 km NE 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 38.1035, -122.2320. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Solano County, CA | 31 km (19 mi) | NE | earthquakes near Solano County |
| Contra Costa County, CA | 32 km (20 mi) | SE | earthquakes near Contra Costa County |
| Marin County, CA | 45 km (28 mi) | W | earthquakes near Marin County |
| Napa County, CA | 46 km (28 mi) | N | earthquakes near Napa County |
| Alameda County, CA | 58 km (36 mi) | SSE | earthquakes near Alameda County |
| Yolo County, CA | 70 km (44 mi) | NNE | earthquakes near Yolo 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.
- 2.0 1km W of Kensington, CA
- 2.5 1km W of Kensington, CA
- 1.7 5km ENE of Vallejo, CA
- 1.6 7km ENE of Kenwood, CA
- 1.9 8km SSW of Brentwood, CA
- 1.6 8km E of Vallejo, CA
- 1.9 1km NE of San Ramon, CA
- 1.7 1km NE of San Ramon, CA
- 1.8 1km NE of San Ramon, CA
- 2.7 2km NE of San Ramon, CA
- 1.6 2km NE of San Ramon, CA
- 2.0 1km NE of San Ramon, CA
- 1.5 1km NE of San Ramon, CA
- 1.6 1km NE of San Ramon, CA
- 1.6 1km NE of San Ramon, 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.