QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

4 km NNW of Orinda, California

· 9.2 km deep · released about 10 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 21 kmAlameda County 39 kmSolano County 45 kmMarin County 51 kmSan Mateo County 58 kmNapa County 67 kmSan Francisco County 76 kmSan Joaquin County 81 kmYolo County 89 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 1.7 (md)
Depth
9.2 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 21 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3313 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 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 37.9147, -122.1948. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 21 km (13 mi) W of here earthquakes near Contra Costa County
Alameda County, CA 39 km (24 mi) NW of here earthquakes near Alameda County
Solano County, CA 45 km (28 mi) SSW of here earthquakes near Solano County
Marin County, CA 51 km (31 mi) ESE of here earthquakes near Marin County
San Mateo County, CA 58 km (36 mi) NNE of here earthquakes near San Mateo County
Napa County, CA 67 km (42 mi) S of here earthquakes near Napa County

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

Aftershocks so far

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

  1. 2.3 2km NW of Pittsburg, CA
  2. 1.6 5km NNW of Pacifica, CA
  3. 2.2 5km NNW of Pacifica, CA
  4. 2.1 2km ENE of Berkeley, CA
  5. 1.6 2km E of Diablo, CA
  6. 1.6 6km ENE of Dublin, CA
  7. 1.8 10km SSE of Elmira, CA
  8. 2.4 10km S of Elmira, CA
  9. 1.6 6km ENE of El Granada, CA
  10. 2.6 2km NNE of San Leandro, CA
  11. 1.7 5km NNE of San Leandro, CA
  12. 2.4 1km E of Pacheco, CA
  13. 1.7 1 km N of North Fair Oaks, California
  14. 1.6 2 km NNW of Pleasant Hill, California
  15. 1.6 11 km S of Muir Beach, 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.