QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mw

3 km NW of Redwood Valley, California

· 1.4 km deep · released about 12 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 24 kmLake County 46 kmGlenn County 80 kmColusa County 87 kmSonoma County 89 kmNapa County 117 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 3.9 (mw)
Depth
1.4 km below the surface
Felt
365 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Mendocino County, 24 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1741 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 365 people have reported feeling it to USGS.

How big was it?

This earthquake released about 12 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 14,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 620× the energy of this one
  3. Magna, Utah 2020 M 5.7 440× the energy of this one
  4. This earthquake M 3.9 about 12 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 26× more

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 39.2847, -123.2342. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 24 km (15 mi) SE of here earthquakes near Mendocino County
Lake County, CA 46 km (29 mi) WNW of here earthquakes near Lake County
Glenn County, CA 80 km (50 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 87 km (54 mi) W of here earthquakes near Colusa County
Sonoma County, CA 89 km (55 mi) NNW of here earthquakes near Sonoma County
Napa County, CA 117 km (73 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

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

  1. 2.0 17km NW of Lake Pillsbury, CA
  2. 1.7 8km W of Boonville, CA
  3. 1.5 6km ESE of Willits, CA
  4. 1.5 18km NE of Upper Lake, CA
  5. 2.0 14km SE of Talmage, CA
  6. 1.9 4km NW of Redwood Valley, CA
  7. 2.0 7km SSE of Laytonville, CA
  8. 2.3 4km S of Boonville, CA
  9. 1.6 13km W of Lake Pillsbury, CA
  10. 1.6 6km SE of Lake Pillsbury, CA
  11. 1.7 10km N of Cloverdale, CA
  12. 1.5 18km NE of Upper Lake, CA
  13. 1.8 12km N of Brooktrails, CA
  14. 1.5 18km NE of Upper Lake, CA
  15. 2.2 13km SW of Lakeport, 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 53 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.