QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

6km W of Sea Ranch, CA

· 1.5 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 56 kmMendocino County 81 kmLake County 81 kmMarin County 100 kmNapa County 107 kmSan Francisco County 117 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
1.5 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 56 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1308 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 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 38.7082, -123.5265. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Sonoma County, CA 56 km (35 mi) WNW of here earthquakes near Sonoma County
Mendocino County, CA 81 km (50 mi) S of here earthquakes near Mendocino County
Lake County, CA 81 km (50 mi) WSW of here earthquakes near Lake County
Marin County, CA 100 km (62 mi) NW of here earthquakes near Marin County
Napa County, CA 107 km (66 mi) WNW of here earthquakes near Napa County
San Francisco County, CA 117 km (73 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

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

  1. 1.5 5 km E of Boonville, CA
  2. 3.1 5 km NNE of Boonville, CA
  3. 1.9 5 km E of Boonville, CA
  4. 2.8 5 km E of Boonville, CA
  5. 1.6 14 km SE of Boonville, CA
  6. 1.6 5 km ESE of Point Arena, CA
  7. 1.6 12 km N of Cloverdale, CA
  8. 1.9 4 km NE of Boonville, CA
  9. 1.5 4 km NE of Boonville, CA
  10. 1.7 13 km NW of Fort Ross, CA
  11. 1.8 14 km NW of Fort Ross, CA
  12. 1.6 14 km NW of Fort Ross, CA
  13. 1.6 13 km NW of Fort Ross, CA
  14. 1.6 6 km N of Guerneville, CA
  15. 1.6 10 km S of Boonville, 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.