QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

15 km ENE of Brooktrails, CA

· 7.5 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 20 kmLake County 61 kmGlenn County 72 kmColusa County 93 kmTehama County 110 kmSonoma County 112 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
7.5 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 20 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 241 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 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 39.5025, -123.2310. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 20 km (12 mi) ENE of here earthquakes near Mendocino County
Lake County, CA 61 km (38 mi) NW of here earthquakes near Lake County
Glenn County, CA 72 km (45 mi) W of here earthquakes near Glenn County
Colusa County, CA 93 km (58 mi) WNW of here earthquakes near Colusa County
Tehama County, CA 110 km (68 mi) SW of here earthquakes near Tehama County
Sonoma County, CA 112 km (69 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

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

  1. 1.9 17 km NNE of Upper Lake, CA
  2. 1.6 10 km ENE of Talmage, CA
  3. 1.6 5 km NE of Brooktrails, CA
  4. 2.0 16 km N of Laytonville, CA
  5. 2.6 16 km N of Laytonville, CA
  6. 2.3 2 km W of Redwood Valley, CA
  7. 1.9 10 km SW of Covelo, CA
  8. 2.0 2 km SSE of Redwood Valley, CA
  9. 2.1 7 km NNE of Redwood Valley, CA
  10. 1.8 7 km N of Lake Pillsbury, CA
  11. 1.6 7 km N of Lake Pillsbury, CA
  12. 1.7 9 km NNE of Brooktrails, CA
  13. 1.9 14 km E of Willits, CA
  14. 2.2 12 km SSE of Laytonville, CA
  15. 1.7 3 km SSE of Redwood Valley, 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 99,000 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.