QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

2 km SSW of Broadmoor, California

· 9.5 km deep · released about 5.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Mateo County 30 kmSan Francisco County 47 kmMarin County 48 kmAlameda County 52 kmContra Costa County 56 kmSolano County 83 kmSanta Cruz County 85 kmSanta Clara County 87 kmNapa County 95 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 1.5 (md)
Depth
9.5 km below the surface
Felt
no reports yet
Nearest
San Mateo County, 30 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3457 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 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 37.6650, -122.4997. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Mateo County, CA 30 km (19 mi) NNW of here earthquakes near San Mateo County
San Francisco County, CA 47 km (29 mi) E of here earthquakes near San Francisco County
Marin County, CA 48 km (30 mi) SSE of here earthquakes near Marin County
Alameda County, CA 52 km (32 mi) W of here earthquakes near Alameda County
Contra Costa County, CA 56 km (35 mi) WSW of here earthquakes near Contra Costa County
Solano County, CA 83 km (52 mi) SW of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 2.2 7 km S of Muir Beach, California
  2. 2.9 7 km SSW of Muir Beach, California
  3. 1.9 0 km NNW of Pleasant Hill, California
  4. 2.0 0 km W of Kensington, California
  5. 1.7 0 km W of Kensington, California
  6. 1.8 0 km E of Hayward, California
  7. 2.0 4 km NNW of Orinda, California
  8. 2.0 4 km NNW of Orinda, California
  9. 1.6 4 km SW of Danville, California
  10. 2.1 2 km SSW of San Ramon, California
  11. 2.2 1 km SSW of San Ramon, California
  12. 2.7 7 km S of Muir Beach, California
  13. 1.8 0 km NNW of Ladera, California
  14. 1.6 1 km N of Ladera, California
  15. 2.0 1 km W of Danville, 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.