QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

1 km SW of Calpella, California

· 5.8 km deep · released about 41 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 30 kmLake County 43 kmSonoma County 81 kmGlenn County 82 kmColusa County 85 kmNapa County 111 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 (md)
Depth
5.8 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 30 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3498 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 41 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 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 39.2223, -123.2165. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 30 km (19 mi) SE of here earthquakes near Mendocino County
Lake County, CA 43 km (26 mi) WNW of here earthquakes near Lake County
Sonoma County, CA 81 km (51 mi) NNW of here earthquakes near Sonoma County
Glenn County, CA 82 km (51 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 85 km (53 mi) W of here earthquakes near Colusa County
Napa County, CA 111 km (69 mi) NW of here earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.6 18 km NE of Upper Lake, California
  2. 2.0 18 km NE of Upper Lake, California
  3. 1.5 9 km ESE of Calpella, California
  4. 2.1 17 km NE of Upper Lake, California
  5. 1.7 9 km N of Redwood Valley, California
  6. 2.3 7 km SSW of Philo, California
  7. 2.2 4 km E of Willits, California
  8. 1.7 11 km SSE of Laytonville, California
  9. 1.6 12 km WSW of Cloverdale, California
  10. 2.4 28 km NNE of Potter Valley, California
  11. 1.7 10km SE of Lake Pillsbury, CA
  12. 1.6 10km SSE of Lake Pillsbury, CA
  13. 1.7 8 km SSE of Laytonville, California
  14. 1.6 5 km E of Hopland, California
  15. 1.6 19 km NNE of Upper Lake, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.1 on 2016-08-10 — it released about 32,000 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.