QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

2 km NE of San Ramon, California

· 19 km deep · released about 10 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 14 kmAlameda County 17 kmSolano County 53 kmSan Mateo County 56 kmSan Joaquin County 62 kmSanta Clara County 68 kmMarin County 75 kmNapa County 85 kmSanta Cruz County 87 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 1.7 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 14 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3356 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 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 37.7950, -121.9590. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 14 km (9 mi) S of here earthquakes near Contra Costa County
Alameda County, CA 17 km (11 mi) NNW of here earthquakes near Alameda County
Solano County, CA 53 km (33 mi) S of here earthquakes near Solano County
San Mateo County, CA 56 km (35 mi) NE of here earthquakes near San Mateo County
San Joaquin County, CA 62 km (39 mi) WSW of here earthquakes near San Joaquin County
Santa Clara County, CA 68 km (42 mi) NNW of here earthquakes near Santa Clara 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. 1.6 1 km NNW of Crockett, California
  2. 2.0 8 km NNE of East Foothills, California
  3. 1.8 Northern California
  4. 2.5 9 km NNE of East Foothills, California
  5. 2.7 1 km SE of Pacheco, California
  6. 1.8 4 km SE of Livermore, California
  7. 2.0 1 km W of Kensington, California
  8. 2.3 3 km N of East Foothills, California
  9. 2.6 3 km N of East Foothills, California
  10. 2.8 3 km NNE of East Foothills, California
  11. 2.0 3 km N of East Foothills, California
  12. 3.3 3 km NNE of East Foothills, California
  13. 1.8 4 km N of East Foothills, California
  14. 1.7 3 km NNE of Danville, California
  15. 2.6 3 km N of East Foothills, 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.