QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8mw

4km ENE of Talmage, CA

· 9.2 km deep · released about 7.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 32 kmMendocino County 42 kmSonoma County 71 kmColusa County 76 kmGlenn County 80 kmNapa County 99 kmYolo County 117 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
Magnitude
M 3.8 (mw)
Depth
9.2 km below the surface
Felt
316 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Lake County, 32 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1775 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 316 people have reported feeling it to USGS.

How big was it?

This earthquake released about 7.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 24,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 760× the energy of this one
  4. This earthquake M 3.8 about 7.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 15× more

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.

Where

Epicentre 39.1465, -123.1180. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, CA 32 km (20 mi) W of here earthquakes near Lake County
Mendocino County, CA 42 km (26 mi) SE of here earthquakes near Mendocino County
Sonoma County, CA 71 km (44 mi) NNW of here earthquakes near Sonoma County
Colusa County, CA 76 km (47 mi) W of here earthquakes near Colusa County
Glenn County, CA 80 km (50 mi) SW of here earthquakes near Glenn County
Napa County, CA 99 km (61 mi) NW of here earthquakes near Napa County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

40 earthquakes have been recorded within 50 km since this one.

  1. 1.7 3km ENE of Talmage, CA
  2. 1.7 4km W of Cobb, CA
  3. 1.5 5km WNW of The Geysers, CA
  4. 1.9 10km NW of The Geysers, CA
  5. 1.6 2km N of The Geysers, CA
  6. 1.7 10km NNW of Redwood Valley, CA
  7. 1.8 16km NE of Upper Lake, CA
  8. 1.8 14km SE of Lake Pillsbury, CA
  9. 2.0 12km ESE of Boonville, CA
  10. 1.7 3km NNW of The Geysers, CA
  11. 1.7 6km NW of The Geysers, CA
  12. 1.7 6km NW of The Geysers, CA
  13. 2.6 3km NW of The Geysers, CA
  14. 1.8 6km SE of Lake Pillsbury, CA
  15. 1.6 6km NW of Boonville, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.1 on 2016-08-10 — it released about 92 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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