QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

8km WSW of Muir Beach, CA

· 4.2 km deep · released about 270 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 26 kmSan Francisco County 34 kmSan Mateo County 53 kmContra Costa County 64 kmAlameda County 69 kmSolano County 80 kmSonoma County 81 kmNapa County 81 kmSanta Cruz County 108 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 2.6 (md)
Depth
4.2 km below the surface
Felt
9 reports · strongest reported intensity III
Nearest
Marin County, 26 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1324 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 9 people have reported feeling it to USGS.

How big was it?

This earthquake released about 270 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 57,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 40,000× the energy of this one
  3. Around the size people start to feel M 3.0 3.6× the energy of this one
  4. This earthquake M 2.6 about 270 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 37.8270, -122.6663. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 26 km (16 mi) SSE of here earthquakes near Marin County
San Francisco County, CA 34 km (21 mi) ENE of here earthquakes near San Francisco County
San Mateo County, CA 53 km (33 mi) NNW of here earthquakes near San Mateo County
Contra Costa County, CA 64 km (40 mi) W of here earthquakes near Contra Costa County
Alameda County, CA 69 km (43 mi) WNW of here earthquakes near Alameda County
Solano County, CA 80 km (50 mi) SW of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.6 7km S of Muir Beach, CA
  2. 2.0 3km SSW of Port Costa, CA
  3. 2.1 1km WNW of Kensington, CA
  4. 1.7 2km ENE of Berkeley, CA
  5. 2.4 1km N of Pacifica, CA
  6. 2.1 5km W of Hillsborough, CA
  7. 1.8 2km N of Lafayette, CA
  8. 2.2 5km WSW of San Francisco Zoo, CA
  9. 1.7 4km SW of Vallejo, CA
  10. 1.8 4km SSE of Highlands-Baywood Park, CA
  11. 2.1 6km NNE of San Leandro, CA
  12. 1.8 6km E of San Rafael, CA
  13. 1.6 5km WSW of Colma, CA
  14. 2.3 5km WSW of Colma, CA
  15. 1.6 4km WSW of San Francisco Zoo, 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 420 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.