QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

Earthquake near San Francisco, CA

USGS: 5 km SSW of Muir Beach, California

16 km (10 mi) WNW of San Francisco, CA

12:20 pm PDT, Jul 9, 2016 · · 5.4 km deep · released about 260 lb of TNT

10 km30 km60 km120 km N Marin County 29 kmSan Francisco County 40 kmSan Mateo County 49 kmContra Costa County 58 kmAlameda County 63 kmSolano County 76 kmNapa County 80 kmSonoma County 84 kmSanta Cruz County 104 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
12:20 pm PDT on 9 July 2016 ()
Where
16 km (10 mi) WNW of San Francisco, CA · earthquakes near San Francisco
Magnitude
M 2.6 (md)
Depth
5.4 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Marin County, 29 km NNW
Nearest mapped fault
San Andreas fault, 1 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 1522 days ago

A magnitude 2.6 earthquake was recorded 16 km (10 mi) WNW of San Francisco, CA, at 12:20 pm PDT on 9 July 2016 (19:20 UTC). 4 people have reported feeling it to USGS. This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

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

How big was it?

This earthquake released about 260 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 59,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 42,000× the energy of this one
  3. Around the size people start to feel M 3.0 3.7× the energy of this one
  4. This earthquake M 2.6 about 260 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 2 earthquakes of M5 or more within 50 km:

  1. 7.9 The 1906 San Francisco, California Earthquake · 9 km SSE of this epicentre
  2. 5.3 The 1957 San Francisco, California Earthquake · 19 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 37.8177, -122.5963. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Marin County, CA 29 km (18 mi) NNW earthquakes near Marin County
San Francisco County, CA 40 km (25 mi) WSW earthquakes near San Francisco County
San Mateo County, CA 49 km (30 mi) SSE earthquakes near San Mateo County
Contra Costa County, CA 58 km (36 mi) ENE earthquakes near Contra Costa County
Alameda County, CA 63 km (39 mi) ESE earthquakes near Alameda County
Solano County, CA 76 km (47 mi) NE earthquakes near Solano County

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

Aftershocks so far

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

  1. 2.1 3 km NNW of Castro Valley, California
  2. 1.6 2 km NE of Pacifica, California
  3. 1.5 5 km WNW of Broadmoor, California
  4. 2.4 2 km SSE of Berkeley, California
  5. 1.6 1 km NW of Acalanes Ridge, California
  6. 2.0 1 km NE of Pacifica, California
  7. 1.5 1 km NNW of Piedmont, California
  8. 2.2 0 km NW of Piedmont, California
  9. 2.3 1 km NW of Piedmont, California
  10. 1.5 2 km NE of Pacifica, California
  11. 1.6 1 km NE of Pacifica, California
  12. 2.9 2 km NE of Pacifica, California
  13. 1.7 2 km NE of Pacifica, California
  14. 1.6 2 km NE of Pacifica, California
  15. 1.7 1 km SSE of East Richmond Heights, 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.