QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

10 km WNW of Cobb, CA

· 0.8 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 30 kmSonoma County 37 kmNapa County 58 kmColusa County 63 kmYolo County 82 kmMendocino County 84 kmMarin County 89 kmGlenn County 92 kmSutter County 100 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 1.8 (md)
Depth
0.8 km below the surface
Felt
no reports yet
Nearest
Lake County, 30 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 769 days ago

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

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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.

Where

Epicentre 38.8463, -122.8283. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, CA 30 km (19 mi) SSW of here earthquakes near Lake County
Sonoma County, CA 37 km (23 mi) NNE of here earthquakes near Sonoma County
Napa County, CA 58 km (36 mi) NW of here earthquakes near Napa County
Colusa County, CA 63 km (39 mi) SW of here earthquakes near Colusa County
Yolo County, CA 82 km (51 mi) WNW of here earthquakes near Yolo County
Mendocino County, CA 84 km (52 mi) SE of here earthquakes near Mendocino County

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

Aftershocks so far

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

  1. 1.7 10 km NNE of Cloverdale, CA
  2. 1.6 7 km ENE of Cloverdale, CA
  3. 1.5 2 km NW of The Geysers, CA
  4. 1.7 10 km NW of The Geysers, CA
  5. 1.5 10 km NW of The Geysers, CA
  6. 1.6 2 km NNW of The Geysers, CA
  7. 1.5 8 km SSW of The Geysers, CA
  8. 1.5 7 km NNW of The Geysers, CA
  9. 1.9 4 km SE of Lower Lake, CA
  10. 1.6 8 km WSW of Cloverdale, CA
  11. 2.0 3 km SSW of Anderson Springs, CA
  12. 1.6 6 km WNW of Cobb, CA
  13. 2.1 7 km S of Calistoga, CA
  14. 1.7 6 km SSW of Calistoga, CA
  15. 2.0 3 km W of Cobb, 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 5.0 on 2016-12-14 — it released about 65,000 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.