QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

33km S of Point Reyes, CA

· 3.8 km deep · released about 120 lb of TNT

10 km30 km60 km120 km N San Francisco County 6 kmMarin County 43 kmSan Mateo County 62 kmSonoma County 91 kmContra Costa County 93 kmAlameda County 93 kmNapa County 105 kmSolano County 110 kmSanta Cruz County 115 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 2.4 (md)
Depth
3.8 km below the surface
Felt
4 reports · strongest reported intensity II
Nearest
San Francisco County, 6 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2490 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 92,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.2× the energy of this one
  4. This earthquake M 2.4 about 120 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 37.7050, -122.9698. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Francisco County, CA 6 km (4 mi) ESE of here earthquakes near San Francisco County
Marin County, CA 43 km (27 mi) SSW of here earthquakes near Marin County
San Mateo County, CA 62 km (38 mi) WNW of here earthquakes near San Mateo County
Sonoma County, CA 91 km (57 mi) S of here earthquakes near Sonoma County
Contra Costa County, CA 93 km (58 mi) WSW of here earthquakes near Contra Costa County
Alameda County, CA 93 km (58 mi) W of here earthquakes near Alameda County

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

Aftershocks so far

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

  1. 1.9 3km ESE of Pacifica, CA
  2. 1.7 5km WSW of Colma, CA
  3. 1.7 3km ESE of Pacifica, CA
  4. 1.9 3km ESE of Pacifica, CA
  5. 1.8 3km ESE of Pacifica, CA
  6. 1.6 19km SW of Point Reyes, CA
  7. 1.7 1km W of Pacifica, CA
  8. 2.2 1km WSW of Pacifica, CA
  9. 1.6 7km S of Muir Beach, CA
  10. 1.8 3km SW of San Francisco Zoo, CA
  11. 1.7 6km WSW of Daly City, CA
  12. 1.5 5km WSW of Daly City, CA
  13. 1.6 4km N of Inverness, CA
  14. 1.6 2km ENE of Pacifica, CA
  15. 1.5 1km SE of Pacifica, 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.