QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

18km W of Ukiah, CA

· 0.7 km deep · released about 82 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 28 kmLake County 58 kmSonoma County 84 kmGlenn County 99 kmColusa County 102 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 2.3 (md)
Depth
0.7 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Mendocino County, 28 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 250 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 82 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 82 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 39.1780, -123.4157. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 28 km (18 mi) S of here earthquakes near Mendocino County
Lake County, CA 58 km (36 mi) W of here earthquakes near Lake County
Sonoma County, CA 84 km (52 mi) NNW of here earthquakes near Sonoma County
Glenn County, CA 99 km (62 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 102 km (63 mi) W of here earthquakes near Colusa County
Napa County, CA 120 km (75 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

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

  1. 2.9 11km N of Brooktrails, CA
  2. 1.5 8km SE of Willits, CA
  3. 1.8 10km SE of Willits, CA
  4. 2.0 15km NE of Point Arena, CA
  5. 1.6 8km E of Willits, CA
  6. 2.2 15km NE of Point Arena, CA
  7. 1.5 4km SSE of Point Arena, CA
  8. 1.5 16km SE of Boonville, CA
  9. 1.5 9km NNW of Redwood Valley, CA
  10. 1.9 5km NE of Ukiah, CA
  11. 1.7 16km WSW of Redwood Valley, CA
  12. 1.7 7km E of Willits, CA
  13. 1.7 21km E of Navarro Head, CA
  14. 2.1 21km E of Navarro Head, CA
  15. 1.6 2km SW of Redwood Valley, 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 4.4 on 2020-12-06 — it released about 1,400 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.