QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

21km SW of Point Arena, CA

· 3.2 km deep · released about 64 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 82 kmSonoma County 85 kmLake County 103 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 2.2 (md)
Depth
3.2 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 82 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1255 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 64 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 230,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 170,000× the energy of this one
  3. Around the size people start to feel M 3.0 15× the energy of this one
  4. This earthquake M 2.2 about 64 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 38.7685, -123.8527. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 82 km (51 mi) SSW of here earthquakes near Mendocino County
Sonoma County, CA 85 km (53 mi) WNW of here earthquakes near Sonoma County
Lake County, CA 103 km (64 mi) WSW of here earthquakes near Lake County
Marin County, CA 125 km (78 mi) NW of here earthquakes near Marin County
San Francisco County, CA 136 km (85 mi) NNW of here earthquakes near San Francisco County

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

Aftershocks so far

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

  1. 1.6 19 km SE of Navarro Head, CA
  2. 1.6 15 km ESE of Navarro Head, CA
  3. 2.5 2 km NNE of Point Arena, CA
  4. 2.1 5 km SW of Boonville, CA
  5. 1.7 11 km WNW of Fort Ross, CA
  6. 1.5 3 km S of Point Arena, CA
  7. 1.7 7 km S of Boonville, CA
  8. 1.6 20 km NW of Boonville, CA
  9. 1.9 6 km SE of Point Arena, CA
  10. 1.8 6 km SW of Boonville, CA
  11. 1.6 16 km ESE of Navarro Head, CA
  12. 2.3 37 km W of Point Arena, CA
  13. 1.8 12 km SE of Point Arena, CA
  14. 1.9 12 km SE of Point Arena, CA
  15. 1.6 2 km NNW of Point Arena, 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.