Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Angwin, CA
No earthquake was likely felt in Angwin in the 24 hours to 3:22 pm PST (23:22 UTC). The last one was M 1.6, in Angwin, at 11:57 pm PDT on 10 October 2026, estimated intensity II (weak) in town. Every earthquake near Angwin
This page: a magnitude 1.6 earthquake was recorded 17 km (11 mi) north-northeast of Angwin, CA, at 1:21 am PDT on 24 April 2023 (08:21 UTC), 7.7 km deep.
USGS: 17km NNE of Angwin, CA
42 km (26 mi) NE of Santa Rosa, CA · 104 km (65 mi) N of San Francisco, CA
- When
- 1:21 am PDT on 24 April 2023 ()
- Where
- 17 km (11 mi) north-northeast of Angwin, CA · earthquakes near Angwin
- Magnitude
- M 1.6 (md)
- Depth
- 7.7 km below the surface
- Felt
- no reports yet
- Nearest
- Napa County, 23 km S
- Nearest mapped fault
- Hunting Creek-Berryessa fault system, 3 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 1297 days ago
Earthquake alerts for Angwin, CA
Get a notification in this browser when USGS records an earthquake near Angwin, 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 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 8 km (5 mi) from the epicentre. In Angwin, 17 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: Hidden Valley Lake, Deer Park, Middletown, Calistoga, Saint Helena, Esparto.
How big was it?
This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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 5.0 on 2016-12-14 — about 130,000 times the energy of this one.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
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 38.7120, -122.3572. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Napa County, CA | 23 km (14 mi) | S | earthquakes near Napa County |
| Yolo County, CA | 40 km (25 mi) | E | earthquakes near Yolo County |
| Colusa County, CA | 53 km (33 mi) | NNE | earthquakes near Colusa County |
| Sonoma County, CA | 54 km (33 mi) | WSW | earthquakes near Sonoma County |
| Lake County, CA | 55 km (34 mi) | NW | earthquakes near Lake County |
| Solano County, CA | 61 km (38 mi) | SE | earthquakes near Solano 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 7km NW of The Geysers, CA
- 2.2 4km SW of Anderson Springs, CA
- 1.9 7km NW of The Geysers, CA
- 1.5 10km WNW of The Geysers, CA
- 2.0 10km WNW of The Geysers, CA
- 1.6 6km NW of The Geysers, CA
- 1.6 9km WNW of Cobb, CA
- 1.6 3km NW of The Geysers, CA
- 1.6 2km ESE of The Geysers, CA
- 1.8 7km NW of The Geysers, CA
- 1.7 4km NNW of The Geysers, CA
- 1.7 7km NW of The Geysers, CA
- 1.7 7km NW of The Geysers, CA
- 1.5 1km WNW of The Geysers, CA
- 1.6 7km NW of The Geysers, 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.