QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

4km NW of Orinda, CA

· 8.4 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Contra Costa County 24 kmAlameda County 39 kmSolano County 48 kmMarin County 49 kmSan Mateo County 55 kmNapa County 68 kmSan Francisco County 74 kmSan Joaquin County 83 kmSanta Clara 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
8.4 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Contra Costa County, 24 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2332 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 12 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 37.8983, -122.2187. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 24 km (15 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 48 km (30 mi) SSW of here earthquakes near Solano County
Marin County, CA 49 km (31 mi) ESE of here earthquakes near Marin County
San Mateo County, CA 55 km (34 mi) NNE of here earthquakes near San Mateo County
Napa County, CA 68 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

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

  1. 3.2 3km ESE of San Leandro, CA
  2. 2.6 3km ESE of San Leandro, CA
  3. 1.8 2km N of Danville, CA
  4. 2.7 2km SSE of Crockett, CA
  5. 2.3 2km NE of El Cerrito, CA
  6. 1.6 4km SSW of Newark, CA
  7. 2.6 6km SW of Clayton, CA
  8. 2.5 6km NE of Alamo, CA
  9. 1.6 5km E of Vallejo, CA
  10. 1.9 6km E of Fremont, CA
  11. 1.9 6km NE of Alamo, CA
  12. 1.6 3km ESE of Union City, CA
  13. 2.5 11km SSW of Brentwood, CA
  14. 2.0 3km SW of American Canyon, CA
  15. 2.3 9km NE of Blackhawk, 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 4.5 on 2019-10-15 — it released about 12,000 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.