QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Angwin, CA

No earthquake was likely felt in Angwin in the 24 hours to 11:24 am PST (19:24 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 1.5 earthquake was recorded 14 km (9 mi) north-northeast of Angwin, CA, at 3:13 pm PST on 8 February 2022 (23:13 UTC), 11 km deep.

USGS: 14km NNE of Angwin, CA

39 km (24 mi) NE of Santa Rosa, CA · 102 km (63 mi) N of San Francisco, CA

3:13 pm PST, Feb 8, 2022 · · 11 km deep · released about 5.6 lb of TNT

10 km30 km60 km120 km N Napa County 22 kmYolo County 43 kmSonoma County 50 kmLake County 55 kmColusa County 55 kmSolano County 62 kmSutter County 71 kmMarin County 78 kmContra Costa County 95 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
3:13 pm PST on 8 February 2022 ()
Where
14 km (9 mi) north-northeast of Angwin, CA · earthquakes near Angwin
Magnitude
M 1.5 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Napa County, 22 km SSE
Nearest mapped fault
Hunting Creek-Berryessa fault system, under 1 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 1732 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Angwin, 14 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.

How big was it?

This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 180,000 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 38.6975, -122.3958. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 22 km (14 mi) SSE earthquakes near Napa County
Yolo County, CA 43 km (27 mi) E earthquakes near Yolo County
Sonoma County, CA 50 km (31 mi) WSW earthquakes near Sonoma County
Lake County, CA 55 km (34 mi) NNW earthquakes near Lake County
Colusa County, CA 55 km (34 mi) NNE earthquakes near Colusa County
Solano County, CA 62 km (39 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. 1.9 14km E of Angwin, CA
  2. 2.1 8km NW of The Geysers, CA
  3. 2.4 4km NNW of The Geysers, CA
  4. 2.0 11km WNW of The Geysers, CA
  5. 1.7 7km W of Cobb, CA
  6. 2.1 1km ENE of The Geysers, CA
  7. 2.7 1km ENE of The Geysers, CA
  8. 1.6 6km WNW of The Geysers, CA
  9. 1.7 10km WNW of The Geysers, CA
  10. 1.5 2km NW of The Geysers, CA
  11. 2.2 3km NW of The Geysers, CA
  12. 2.0 2km W of Anderson Springs, CA
  13. 2.1 14km ESE of Hidden Valley Lake, CA
  14. 1.6 7km WNW of Cobb, CA
  15. 1.5 4km SE 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.