QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

8 km ENE of Point Arena, CA

· 4.8 km deep · released about 21 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 58 kmSonoma County 74 kmLake County 77 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 1.9 (md)
Depth
4.8 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 58 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 257 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 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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 38.9282, -123.6060. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 58 km (36 mi) SSW of here earthquakes near Mendocino County
Sonoma County, CA 74 km (46 mi) NW of here earthquakes near Sonoma County
Lake County, CA 77 km (48 mi) WSW of here earthquakes near Lake County
Napa County, CA 121 km (75 mi) WNW of here earthquakes near Napa County
Colusa County, CA 121 km (75 mi) WSW of here earthquakes near Colusa County
Marin County, CA 123 km (76 mi) NW of here earthquakes near Marin County

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

Aftershocks so far

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

  1. 2.0 8 km SW of Redwood Valley, CA
  2. 2.0 14 km S of Willits, CA
  3. 2.7 7 km E of Navarro Head, CA
  4. 1.9 20 km ENE of Navarro Head, CA
  5. 1.9 5 km NE of Ukiah, CA
  6. 1.8 3 km S of Redwood Valley, CA
  7. 1.7 5 km E of Point Arena, CA
  8. 1.7 8 km S of Boonville, CA
  9. 2.2 21 km ENE of Navarro Head, CA
  10. 1.7 13 km WNW of Ukiah, CA
  11. 1.6 19 km SW of Cloverdale, CA
  12. 1.5 18 km SW of Cloverdale, CA
  13. 1.5 18 km ENE of Navarro Head, CA
  14. 1.6 3 km SSE of Redwood Valley, CA
  15. 1.6 5 km NE of Ukiah, 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 5,600 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.