QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

2km W of Concord, CA

· 3.1 km deep · released about 7.3 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 9 kmSolano County 34 kmAlameda County 37 kmMarin County 63 kmNapa County 65 kmSan Joaquin County 67 kmSan Mateo County 69 kmYolo County 80 kmSacramento County 80 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 1.6 (md)
Depth
3.1 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 9 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1966 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 7.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 37.9703, -122.0315. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 9 km (6 mi) NW of here earthquakes near Contra Costa County
Solano County, CA 34 km (21 mi) SSW of here earthquakes near Solano County
Alameda County, CA 37 km (23 mi) NNW of here earthquakes near Alameda County
Marin County, CA 63 km (39 mi) E of here earthquakes near Marin County
Napa County, CA 65 km (40 mi) SSE of here earthquakes near Napa County
San Joaquin County, CA 67 km (41 mi) W of here earthquakes near San Joaquin County

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

Aftershocks so far

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

  1. 1.8 1km ENE of Alamo, CA
  2. 1.7 5km WNW of Dublin, CA
  3. 1.5 5km E of Fremont, CA
  4. 1.6 1km NE of Berkeley, CA
  5. 1.8 10km NE of Napa, CA
  6. 2.0 1km NNW of Pleasant Hill, CA
  7. 1.6 9km WSW of Mountain House, CA
  8. 1.5 2km ESE of Berkeley, CA
  9. 1.5 4km E of Moraga, CA
  10. 2.2 4km NNE of Blackhawk, CA
  11. 2.5 4km NNE of Blackhawk, CA
  12. 2.0 4km NE of Blackhawk, CA
  13. 1.6 9km WSW of Mountain House, CA
  14. 2.3 2km WNW of Concord, CA
  15. 1.7 2km E of Berkeley, 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 20,000 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.