QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near San Francisco, CA

USGS: 0 km WSW of Muir Beach, California

17 km (11 mi) WNW of San Francisco, CA · 15 km (10 mi) SSW of San Rafael, CA

5:23 pm PDT, Aug 12, 2016 · · 3.3 km deep · released about 30 lb of TNT

Every earthquake near San Francisco Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 25 kmSan Francisco County 42 kmSan Mateo County 53 kmContra Costa County 56 kmAlameda County 64 kmSolano County 73 kmNapa County 76 kmSonoma County 80 kmSanta Clara County 106 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
5:23 pm PDT on 12 August 2016 ()
Where
18 km (11 mi) WNW of San Francisco, CA · earthquakes near San Francisco
Magnitude
M 2.0 (md)
Depth
3.3 km below the surface
Felt
no reports yet
Nearest
Marin County, 25 km NNW
Nearest mapped fault
San Andreas fault, 2 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3521 days ago

A magnitude 2.0 earthquake was recorded 18 km (11 mi) WNW of San Francisco, CA, at 5:23 pm PDT on 12 August 2016 (00:23 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Tamalpais Valley, Tamalpais-Homestead Valley, Mill Valley, Marin City, Strawberry, Sausalito.

How big was it?

This earthquake released about 30 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 350,000× the energy of this one
  3. Around the size people start to feel M 3.0 32× the energy of this one
  4. This earthquake M 2.0 about 30 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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 7.9 The 1906 San Francisco, California Earthquake · 13 km SSE of this epicentre
  2. 6.0 The 2014 South Napa, California Earthquake · 46 km NNE of this epicentre
  3. 5.3 The 1957 San Francisco, California Earthquake · 23 km SSE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 37.8585, -122.5893. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Marin County, CA 25 km (16 mi) NNW earthquakes near Marin County
San Francisco County, CA 42 km (26 mi) WSW earthquakes near San Francisco County
San Mateo County, CA 53 km (33 mi) SSE earthquakes near San Mateo County
Contra Costa County, CA 56 km (35 mi) E earthquakes near Contra Costa County
Alameda County, CA 64 km (40 mi) ESE earthquakes near Alameda County
Solano County, CA 73 km (45 mi) NE earthquakes near Solano County

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

Aftershocks so far

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

  1. 2.4 3 km ENE of Vallejo, California
  2. 2.0 1 km S of Hillsborough, California
  3. 1.8 2 km E of Berkeley, California
  4. 2.6 2 km SSW of Alamo, California
  5. 1.9 1 km E of Pacifica, California
  6. 1.6 2 km E of Pacifica, California
  7. 1.8 2 km E of Pacifica, California
  8. 1.6 2 km ENE of San Leandro, California
  9. 1.8 2 km NE of Pacifica, California
  10. 1.8 3 km NNW of Castro Valley, California
  11. 2.1 3 km NNW of Castro Valley, California
  12. 1.6 2 km NE of Pacifica, California
  13. 1.5 5 km WNW of Broadmoor, California
  14. 2.4 2 km SSE of Berkeley, California
  15. 1.9 1 km WSW of Concord, California

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.