QuakeIndex

chemical explosion · reviewed by a seismologist

M 1.6md

9km WSW of Mountain House, CA

· -0.1 km deep · released about 7.8 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 27 kmContra Costa County 34 kmSan Joaquin County 38 kmSanta Clara County 59 kmStanislaus County 59 kmSolano County 64 kmSan Mateo County 75 kmSacramento County 82 kmSanta Cruz County 88 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
no reports yet
Nearest
Alameda County, 27 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1886 days ago

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

USGS catalogues this as chemical explosion, not an earthquake.

How big was it?

This earthquake released about 7.8 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 1,900,000× 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 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 7.8 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 37.7477, -121.6293. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alameda County, CA 27 km (17 mi) ENE of here earthquakes near Alameda County
Contra Costa County, CA 34 km (21 mi) SE of here earthquakes near Contra Costa County
San Joaquin County, CA 38 km (23 mi) WSW of here earthquakes near San Joaquin County
Santa Clara County, CA 59 km (36 mi) N of here earthquakes near Santa Clara County
Stanislaus County, CA 59 km (37 mi) WNW of here earthquakes near Stanislaus County
Solano County, CA 64 km (40 mi) SSE of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.5 3km SSW of Clayton, CA
  2. 1.9 1km S of San Ramon, CA
  3. 1.6 9km SE of Sunol, CA
  4. 1.6 5km SW of Clayton, CA
  5. 2.8 16km SSE of Livermore, CA
  6. 2.1 4km WSW of Alamo, CA
  7. 2.1 6km SSW of Moraga, CA
  8. 1.9 5km SW of Pacheco, CA
  9. 1.8 2km SE of Pacheco, CA
  10. 1.6 1km S of Blackhawk, CA
  11. 2.7 0km N of Byron, CA
  12. 2.0 19km NE of Alum Rock, CA
  13. 1.5 3km N of San Leandro, CA
  14. 3.4 3km N of San Leandro, CA
  15. 1.7 8km NNE of Alum Rock, 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.