QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mw

2km WNW of Cobb, CA

· 0.5 km deep · released about 29 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 31 kmSonoma County 37 kmNapa County 51 kmColusa County 59 kmYolo County 75 kmMarin County 87 kmMendocino County 90 kmGlenn County 91 kmSutter County 93 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 4.2 (mw)
Depth
0.5 km below the surface
Felt
82 reports · strongest reported intensity V
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Nearest
Lake County, 31 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1485 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 82 people have reported feeling it to USGS.

How big was it?

This earthquake released about 29 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 5,800× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 260× the energy of this one
  3. Magna, Utah 2020 M 5.7 180× the energy of this one
  4. This earthquake M 4.2 about 29 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 61× 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 38.8302, -122.7472. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, CA 31 km (19 mi) S of here earthquakes near Lake County
Sonoma County, CA 37 km (23 mi) NNE of here earthquakes near Sonoma County
Napa County, CA 51 km (32 mi) NW of here earthquakes near Napa County
Colusa County, CA 59 km (36 mi) SW of here earthquakes near Colusa County
Yolo County, CA 75 km (47 mi) WNW of here earthquakes near Yolo County
Marin County, CA 87 km (54 mi) N of here earthquakes near Marin County

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

Aftershocks so far

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

  1. 2.0 2km W of Anderson Springs, CA
  2. 1.8 8km WNW of Cobb, CA
  3. 1.5 13km ESE of Angwin, CA
  4. 1.9 7km WNW of Cobb, CA
  5. 1.6 8km WNW of Cobb, CA
  6. 2.2 7km NW of The Geysers, CA
  7. 2.6 2km NNW of The Geysers, CA
  8. 1.6 2km ESE of The Geysers, CA
  9. 1.9 7km NNE of Cloverdale, CA
  10. 2.4 7km ENE of Hidden Valley Lake, CA
  11. 2.4 8km NW of The Geysers, CA
  12. 1.5 6km WNW of The Geysers, CA
  13. 2.8 4km SW of Anderson Springs, CA
  14. 2.0 4km SSW of Anderson Springs, CA
  15. 1.9 8km 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.0 on 2016-12-14 — it released about 17 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.