QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

11km N of Brooktrails, CA

· 7.3 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 14 kmLake County 72 kmGlenn County 83 kmColusa County 105 kmTehama County 116 kmSonoma County 119 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 2.9 (md)
Depth
7.3 km below the surface
Felt
22 reports · strongest reported intensity III
Nearest
Mendocino County, 14 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1114 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 22 people have reported feeling it to USGS.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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 39.5413, -123.3642. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 14 km (9 mi) NNE of here earthquakes near Mendocino County
Lake County, CA 72 km (45 mi) NW of here earthquakes near Lake County
Glenn County, CA 83 km (51 mi) W of here earthquakes near Glenn County
Colusa County, CA 105 km (65 mi) WNW of here earthquakes near Colusa County
Tehama County, CA 116 km (72 mi) WSW of here earthquakes near Tehama County
Sonoma County, CA 119 km (74 mi) NNW of here earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 1.9 16 km ESE of Navarro Head, CA
  2. 2.0 7 km ESE of Willits, CA
  3. 2.2 9 km NNE of Rockport, CA
  4. 1.5 5 km N of Redwood Valley, CA
  5. 1.6 14 km NW of Laytonville, CA
  6. 2.3 14 km NW of Laytonville, CA
  7. 1.5 13 km NNE of Brooktrails, CA
  8. 1.9 2 km NW of Redwood Valley, CA
  9. 1.5 8 km SE of Willits, CA
  10. 2.3 6 km W of Laytonville, CA
  11. 1.7 16 km N of Covelo, CA
  12. 1.7 16 km N of Covelo, CA
  13. 1.7 7 km WSW of Laytonville, CA
  14. 1.6 5 km NW of Lake Pillsbury, CA
  15. 1.9 13 km SSE of Laytonville, 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 2019-04-29 — it released about 130 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.