QuakeIndex

quarry blast · reviewed by a seismologist

M 1.5md

6 km SSE of Napa, CA

· -0.2 km deep · released about 5.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 26 kmNapa County 29 kmContra Costa County 45 kmMarin County 50 kmYolo County 55 kmSonoma County 67 kmAlameda County 74 kmSacramento County 81 kmSan Francisco County 91 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
-0.2 km below the surface
Felt
no reports yet
Nearest
Solano County, 26 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 527 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 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 38.2580, -122.2415. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Solano County, CA 26 km (16 mi) W of here earthquakes near Solano County
Napa County, CA 29 km (18 mi) SSE of here earthquakes near Napa County
Contra Costa County, CA 45 km (28 mi) NW of here earthquakes near Contra Costa County
Marin County, CA 50 km (31 mi) ENE of here earthquakes near Marin County
Yolo County, CA 55 km (34 mi) SSW of here earthquakes near Yolo County
Sonoma County, CA 67 km (41 mi) ESE of here earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 1.7 1 km S of East Richmond Heights, CA
  2. 2.1 6 km ENE of Vallejo, CA
  3. 1.6 3 km SW of Clayton, CA
  4. 1.6 6 km SSE of Napa, CA
  5. 1.7 3 km SW of Clayton, CA
  6. 2.0 6 km SSW of Calistoga, CA
  7. 1.6 2 km NNW of Walnut Creek, CA
  8. 2.5 2 km NW of Walnut Creek, CA
  9. 1.8 11 km ESE of Angwin, CA
  10. 1.8 7 km E of Vallejo, CA
  11. 1.5 3 km SW of Clayton, CA
  12. 1.9 3 km ESE of Walnut Creek, CA
  13. 2.2 13 km SE of Suisun City, CA
  14. 1.6 7 km ESE of Santa Venetia, CA
  15. 2.7 6 km ESE of Clayton, 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 27,000 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.