QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

2km NW of Bay Point, CA

· -0.1 km deep · released about 7.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 14 kmSolano County 25 kmAlameda County 45 kmNapa County 60 kmSan Joaquin County 63 kmMarin County 67 kmYolo County 71 kmSacramento County 72 kmSan Mateo County 78 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
-0.1 km below the surface
Felt
1 report · strongest reported intensity IV
Nearest
Contra Costa County, 14 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2099 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 7.6 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 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× 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 7.6 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 38.0440, -121.9812. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 14 km (9 mi) N of here earthquakes near Contra Costa County
Solano County, CA 25 km (16 mi) S of here earthquakes near Solano County
Alameda County, CA 45 km (28 mi) N of here earthquakes near Alameda County
Napa County, CA 60 km (37 mi) SSE of here earthquakes near Napa County
San Joaquin County, CA 63 km (39 mi) WNW of here earthquakes near San Joaquin County
Marin County, CA 67 km (42 mi) E of here earthquakes near Marin County

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

Aftershocks so far

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

  1. 1.9 6km SW of Clayton, CA
  2. 1.7 2km ESE of Berkeley, CA
  3. 1.8 2km ESE of Berkeley, CA
  4. 1.5 4km NW of Dublin, CA
  5. 1.6 1km ENE of Alameda, CA
  6. 1.9 1km N of East Richmond Heights, CA
  7. 1.6 2km W of Concord, CA
  8. 1.5 0km NW of Danville, CA
  9. 2.1 1km WNW of Danville, CA
  10. 2.8 2km N of Piedmont, CA
  11. 1.5 5km E of Vallejo, CA
  12. 2.5 2km N of Piedmont, CA
  13. 1.8 3km WSW of Oakley, CA
  14. 1.9 10km SSE of Elmira, CA
  15. 1.8 3km S of Concord, 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 19,000 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.