QuakeIndex

Earthquake · reviewed by a seismologist

M 3.6mw

4km SE of Point Arena, CA

· 9.1 km deep · released about 4.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 63 kmSonoma County 75 kmLake County 83 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 3.6 (mw)
Depth
9.1 km below the surface
Felt
122 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Mendocino County, 63 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 878 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 122 people have reported feeling it to USGS.

How big was it?

This earthquake released about 4.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 42,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,300× the energy of this one
  4. This earthquake M 3.6 about 4.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 8.5× 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 38.8905, -123.6595. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 63 km (39 mi) SSW of here earthquakes near Mendocino County
Sonoma County, CA 75 km (47 mi) WNW of here earthquakes near Sonoma County
Lake County, CA 83 km (51 mi) WSW of here earthquakes near Lake County
Marin County, CA 123 km (76 mi) NW of here earthquakes near Marin County
Napa County, CA 123 km (77 mi) WNW of here earthquakes near Napa County
Glenn County, CA 134 km (83 mi) SW of here earthquakes near Glenn County

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

Aftershocks so far

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

  1. 1.9 5 km E of Boonville, CA
  2. 2.8 5 km E of Boonville, CA
  3. 1.6 14 km SE of Boonville, CA
  4. 1.6 5 km ESE of Point Arena, CA
  5. 1.9 4 km NE of Boonville, CA
  6. 1.5 4 km NE of Boonville, CA
  7. 1.6 22 km E of Navarro Head, CA
  8. 1.7 13 km NW of Fort Ross, CA
  9. 1.8 14 km NW of Fort Ross, CA
  10. 1.6 14 km NW of Fort Ross, CA
  11. 1.6 13 km NW of Fort Ross, CA
  12. 1.6 15 km ESE of Navarro Head, CA
  13. 2.0 12 km E of Navarro Head, CA
  14. 1.6 10 km S of Boonville, CA
  15. 1.7 11 km SE 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.