QuakeIndex

quarry blast · reviewed by a seismologist

M 2.1mh

8 km WSW of Calistoga, CA

· -0.7 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 23 kmNapa County 30 kmMarin County 56 kmLake County 62 kmYolo County 67 kmSolano County 70 kmColusa County 78 kmContra Costa County 94 kmSan Francisco County 98 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 2.1 (mh)
Depth
-0.7 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Sonoma County, 23 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1135 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 1 person has reported feeling it to USGS.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 38.5547, -122.6598. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Sonoma County, CA 23 km (15 mi) E of here earthquakes near Sonoma County
Napa County, CA 30 km (18 mi) W of here earthquakes near Napa County
Marin County, CA 56 km (35 mi) N of here earthquakes near Marin County
Lake County, CA 62 km (39 mi) S of here earthquakes near Lake County
Yolo County, CA 67 km (42 mi) WSW of here earthquakes near Yolo County
Solano County, CA 70 km (44 mi) WNW of here earthquakes near Solano County

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

Aftershocks so far

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

  1. 1.8 11 km E of Yountville, CA
  2. 2.0 7 km NW of The Geysers, CA
  3. 1.8 7 km NW of The Geysers, CA
  4. 1.5 7 km NW of The Geysers, CA
  5. 1.5 4 km W of Cobb, CA
  6. 1.7 1 km NE of The Geysers, CA
  7. 1.7 3 km NNW of The Geysers, CA
  8. 1.5 2 km W of Anderson Springs, CA
  9. 1.7 8 km WNW of Cobb, CA
  10. 2.4 4 km W of Glen Ellen, CA
  11. 1.6 7 km WNW of Yountville, CA
  12. 1.6 3 km NE of The Geysers, CA
  13. 1.7 10 km WNW of The Geysers, CA
  14. 1.6 7 km WNW of Cobb, CA
  15. 1.8 3 km WNW of Boyes Hot Springs, 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 5.0 on 2016-12-14 — it released about 23,000 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.