Earthquake · reviewed by a seismologist
M 2.8ml
Earthquake near Allendale, CA
No earthquake was likely felt in Allendale in the 24 hours to 1:36 am PST (09:36 UTC). The last one was M 3.8, 79 km (49 mi) SSW, at 8:30 am PDT on 13 August 2026, estimated intensity II (weak) in town; 7,876 felt reports to USGS. Every earthquake near Allendale
This page: a magnitude 2.8 earthquake was recorded 6 km (4 mi) west-northwest of Allendale, CA, at 1:02 am PST on 31 December 2022 (09:02 UTC), 19 km deep. 79 people have reported feeling it to USGS.
USGS: 6km WNW of Allendale, CA
12 km (7 mi) NNW of Vacaville, CA · 49 km (31 mi) WSW of Sacramento, CA
- When
- 1:02 am PST on 31 December 2022 ()
- Where
- 6 km (4 mi) west-northwest of Allendale, CA · earthquakes near Allendale
- Magnitude
- M 2.8 (ml)
- Depth
- 19 km below the surface
- Felt
- 79 reports · strongest reported intensity III
- Nearest
- Solano County, 22 km SSE
- Nearest mapped fault
- Great Valley thrust fault system, 2 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 1346 days ago
Earthquake alerts for Allendale, 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 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 19 km (12 mi) from the epicentre. In Allendale, 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: Vacaville 11 km, intensity II · Dixon 17 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 420 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 36,000× the energy of this one
- Magna, Utah 2020 M 5.7 26,000× the energy of this one
- Around the size people start to feel M 3.0 2.3× the energy of this one
- This earthquake M 2.8 about 420 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 4.1 on 2022-06-02 — about 120 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 37 km SW of this epicentre
- 5.4 South of Elmira, California · 20 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 38.4573, -122.0150. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Solano County, CA | 22 km (14 mi) | SSE | earthquakes near Solano County |
| Yolo County, CA | 27 km (17 mi) | NNE | earthquakes near Yolo County |
| Napa County, CA | 28 km (17 mi) | WNW | earthquakes near Napa County |
| Sacramento County, CA | 58 km (36 mi) | E | earthquakes near Sacramento County |
| Contra Costa County, CA | 60 km (37 mi) | S | earthquakes near Contra Costa County |
| Sutter County, CA | 70 km (43 mi) | NNE | earthquakes near Sutter 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.
- 1.9 12 km SE of Middletown, CA
- 1.6 14 km NNE of Angwin, CA
- 1.6 11 km ENE of Yountville, CA
- 1.6 12 km SE of Middletown, CA
- 1.6 12 km SE of Middletown, CA
- 1.8 12 km SE of Middletown, CA
- 2.4 12 km SE of Middletown, CA
- 1.6 15 km SE of Hidden Valley Lake, CA
- 1.5 12 km SE of Middletown, CA
- 2.3 12 km SE of Middletown, CA
- 1.5 12 km SE of Middletown, CA
- 1.6 12 km SE of Middletown, CA
- 1.8 11 km E of Yountville, CA
- 2.2 1 km NW of Green Valley, CA
- 1.6 7 km WNW of Yountville, 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.