QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

3km WSW of Navarro Head, CA

· 5.2 km deep · released about 44 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 41 kmLake County 91 kmSonoma County 105 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
5.2 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Mendocino County, 41 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1512 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 3 people have reported feeling it to USGS.

How big was it?

This earthquake released about 44 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 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× 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 44 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 39.1817, -123.7945. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 41 km (26 mi) SW of here earthquakes near Mendocino County
Lake County, CA 91 km (56 mi) W of here earthquakes near Lake County
Sonoma County, CA 105 km (65 mi) NW of here earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 2.2 9km SSE of Willits, CA
  2. 2.1 7km NE of Fort Bragg, CA
  3. 2.4 16km ESE of Navarro Head, CA
  4. 2.5 8km W of Boonville, CA
  5. 2.5 8km ESE of Willits, CA
  6. 1.6 13km NW of Sea Ranch, CA
  7. 2.2 6km ESE of Willits, CA
  8. 2.0 12km NW of Boonville, CA
  9. 1.8 7km SE of Willits, CA
  10. 2.0 7km SE of Willits, CA
  11. 2.2 20km WNW of Boonville, CA
  12. 1.8 7km W of Redwood Valley, CA
  13. 2.2 5km N of Fort Bragg, CA
  14. 1.8 5km E of Boonville, CA
  15. 1.7 17km NE of Fort Bragg, 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 4.3 on 2017-12-14 — it released about 1,700 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.