QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

4 km W of Pleasant Hill, California

· 10 km deep · released about 9 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 15 kmSolano County 38 kmAlameda County 38 kmMarin County 57 kmSan Mateo County 64 kmNapa County 64 kmSan Joaquin County 74 kmYolo County 83 kmSan Francisco County 85 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
10 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 15 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3427 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 9 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 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 9 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 37.9543, -122.1122. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 15 km (9 mi) WNW of here earthquakes near Contra Costa County
Solano County, CA 38 km (24 mi) SSW of here earthquakes near Solano County
Alameda County, CA 38 km (24 mi) NNW of here earthquakes near Alameda County
Marin County, CA 57 km (35 mi) E of here earthquakes near Marin County
San Mateo County, CA 64 km (40 mi) NNE of here earthquakes near San Mateo County
Napa County, CA 64 km (40 mi) SSE of here earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.7 4 km NNW of Orinda, California
  2. 2.6 2 km ESE of Berkeley, California
  3. 1.9 4 km NNW of Orinda, California
  4. 1.5 Northern California
  5. 1.6 4 km SE of Piedmont, California
  6. 1.5 9 km ESE of Black Point-Green Point, California
  7. 2.2 7 km S of Muir Beach, California
  8. 2.9 7 km SSW of Muir Beach, California
  9. 1.9 0 km NNW of Pleasant Hill, California
  10. 1.8 7 km ENE of Napa, California
  11. 2.0 0 km W of Kensington, California
  12. 1.7 0 km W of Kensington, California
  13. 1.8 0 km E of Hayward, California
  14. 2.0 4 km NNW of Orinda, California
  15. 2.2 0 km ESE of North Gate, 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.