QuakeIndex

quarry blast · reviewed by a seismologist

M 1.6md

6km E of Santa Venetia, CA

· -0.0 km deep · released about 6.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 27 kmContra Costa County 45 kmSolano County 54 kmNapa County 59 kmSan Francisco County 59 kmAlameda County 61 kmSan Mateo County 64 kmSonoma County 73 kmYolo County 90 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
-0.0 km below the surface
Felt
no reports yet
Nearest
Marin County, 27 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1300 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 6.6 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 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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 37.9898, -122.4518. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 27 km (17 mi) ESE of here earthquakes near Marin County
Contra Costa County, CA 45 km (28 mi) W of here earthquakes near Contra Costa County
Solano County, CA 54 km (34 mi) SW of here earthquakes near Solano County
Napa County, CA 59 km (36 mi) S of here earthquakes near Napa County
San Francisco County, CA 59 km (36 mi) ENE of here earthquakes near San Francisco County
Alameda County, CA 61 km (38 mi) NW of here earthquakes near Alameda County

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

Aftershocks so far

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

  1. 1.5 1 km N of Pacifica, CA
  2. 1.6 4km E of Berkeley, CA
  3. 1.6 4km WNW of San Francisco Zoo, CA
  4. 1.6 7km S of Muir Beach, CA
  5. 2.0 3km SSW of Port Costa, CA
  6. 2.1 1km WNW of Kensington, CA
  7. 1.7 2km ENE of Berkeley, CA
  8. 1.5 1km ENE of Vine Hill, CA
  9. 1.5 1km S of Green Valley, CA
  10. 2.4 1km N of Pacifica, CA
  11. 2.1 5km W of Hillsborough, CA
  12. 1.8 7km ENE of Vallejo, CA
  13. 1.8 2km N of Lafayette, CA
  14. 2.0 7km E of Penngrove, CA
  15. 2.2 5km WSW of San Francisco Zoo, 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 22,000 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.