QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

4km SSE of Point Arena, CA

· 1.4 km deep · released about 5.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 64 kmSonoma County 76 kmLake County 84 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 1.5 (md)
Depth
1.4 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 64 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1186 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 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 38.8850, -123.6730. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 64 km (40 mi) SSW of here earthquakes near Mendocino County
Sonoma County, CA 76 km (47 mi) WNW of here earthquakes near Sonoma County
Lake County, CA 84 km (52 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 124 km (77 mi) WNW of here earthquakes near Napa County
Glenn County, CA 135 km (84 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

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

  1. 1.6 20 km NW of Boonville, CA
  2. 1.8 18 km of Boonville, CA
  3. 1.9 6 km SE of Point Arena, CA
  4. 1.8 6 km SW of Boonville, CA
  5. 1.6 16 km ESE of Navarro Head, CA
  6. 2.3 37 km W of Point Arena, CA
  7. 1.8 12 km SE of Point Arena, CA
  8. 1.9 12 km SE of Point Arena, CA
  9. 1.6 2 km NNW of Point Arena, CA
  10. 1.9 9 km SSW of Boonville, CA
  11. 1.5 5 km E of Boonville, CA
  12. 1.9 20 km SSW of Willits, CA
  13. 1.8 16 km ESE of Navarro Head, CA
  14. 3.1 5 km NNE of Boonville, CA
  15. 1.5 23 km SSW of Willits, 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.