QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

9km NNW of Redwood Valley, CA

· 7.2 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 20 kmLake County 50 kmGlenn County 77 kmColusa County 88 kmSonoma County 95 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 1.8 (md)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 20 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1733 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 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 39.3463, -123.2367. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 20 km (13 mi) ESE of here earthquakes near Mendocino County
Lake County, CA 50 km (31 mi) WNW of here earthquakes near Lake County
Glenn County, CA 77 km (48 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 88 km (55 mi) WNW of here earthquakes near Colusa County
Sonoma County, CA 95 km (59 mi) NNW of here earthquakes near Sonoma County
Tehama County, CA 122 km (76 mi) SW of here earthquakes near Tehama County

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

Aftershocks so far

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

  1. 1.8 9km NNW of Redwood Valley, CA
  2. 1.7 9km SE of Willits, CA
  3. 1.6 9km SE of Willits, CA
  4. 2.0 12km WNW of Lakeport, CA
  5. 1.8 4km SSE of Redwood Valley, CA
  6. 2.0 18km SW of Willits, CA
  7. 2.3 6km NW of Redwood Valley, CA
  8. 1.7 7km NE of Willits, CA
  9. 1.7 6km E of Lake Pillsbury, CA
  10. 2.0 7km NNW of Redwood Valley, CA
  11. 1.8 20km ENE of Navarro Head, CA
  12. 1.7 8km WNW of Upper Lake, CA
  13. 1.7 5km E of Lake Pillsbury, CA
  14. 1.8 1km ESE of Lake Pillsbury, CA
  15. 1.9 18km SW of Willits, 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 5.1 on 2016-08-10 — it released about 75,000 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.