QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

7km WSW of Lagunitas-Forest Knolls, CA

· 5.5 km deep · released about 8.1 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 7 kmSan Francisco County 38 kmSonoma County 61 kmNapa County 69 kmContra Costa County 71 kmSan Mateo County 73 kmSolano County 78 kmAlameda County 84 kmYolo County 107 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 1.6 (md)
Depth
5.5 km below the surface
Felt
no reports yet
Nearest
Marin County, 7 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1746 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 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 8.1 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 37.9923, -122.7598. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 7 km (4 mi) S of here earthquakes near Marin County
San Francisco County, CA 38 km (24 mi) NE of here earthquakes near San Francisco County
Sonoma County, CA 61 km (38 mi) SSE of here earthquakes near Sonoma County
Napa County, CA 69 km (43 mi) SSW of here earthquakes near Napa County
Contra Costa County, CA 71 km (44 mi) W of here earthquakes near Contra Costa County
San Mateo County, CA 73 km (45 mi) NNW of here earthquakes near San Mateo County

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

Aftershocks so far

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

  1. 2.2 4km W of San Francisco Zoo, CA
  2. 1.9 2km ENE of Berkeley, CA
  3. 1.7 3km ESE of Berkeley, CA
  4. 2.0 3km ESE of Berkeley, CA
  5. 2.4 3km ESE of Berkeley, CA
  6. 2.9 3km ESE of Berkeley, CA
  7. 2.7 4km E of Sonoma, CA
  8. 1.5 9km SW of Point Reyes, CA
  9. 2.9 2km N of Piedmont, CA
  10. 1.9 3km ESE of Berkeley, CA
  11. 1.8 2km SW of San Francisco Zoo, CA
  12. 1.5 7km E of Santa Venetia, CA
  13. 1.6 6km W of Kenwood, CA
  14. 1.7 5km WSW of Colma, CA
  15. 1.5 4km WNW of Orinda, 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 4.4 on 2018-01-04 — it released about 14,000 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.