QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

21km N of Laytonville, CA

· 6.7 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 50 kmTrinity County 93 kmHumboldt County 99 kmGlenn County 100 kmLake County 108 kmTehama County 113 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
6.7 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 50 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2890 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 14 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 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 39.8742, -123.5217. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 50 km (31 mi) N of here earthquakes near Mendocino County
Trinity County, CA 93 km (58 mi) SSW of here earthquakes near Trinity County
Humboldt County, CA 99 km (61 mi) SSE of here earthquakes near Humboldt County
Glenn County, CA 100 km (62 mi) WNW of here earthquakes near Glenn County
Lake County, CA 108 km (67 mi) NW of here earthquakes near Lake County
Tehama County, CA 113 km (70 mi) WSW of here earthquakes near Tehama County

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

Aftershocks so far

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

  1. 2.0 42km N of Covelo, CA
  2. 2.0 7km ENE of Brooktrails, CA
  3. 1.5 4km NNW of Redway, CA
  4. 1.8 14km NNE of Brooktrails, CA
  5. 1.9 6km NW of Redway, CA
  6. 1.8 3km N of Brooktrails, CA
  7. 1.5 9km ESE of Redway, CA
  8. 1.6 12km N of Brooktrails, CA
  9. 1.5 14km SE of Covelo, CA
  10. 1.8 7km ENE of Brooktrails, CA
  11. 1.8 14km NNE of Brooktrails, CA
  12. 1.7 15km NNE of Brooktrails, CA
  13. 2.4 15km N of Brooktrails, CA
  14. 1.6 7km NE of Brooktrails, CA
  15. 1.5 6km NW of Redway, 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 5,200 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.