QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

30km NW of Covelo, CA

· 7.8 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 60 kmTrinity County 82 kmHumboldt County 89 kmGlenn County 104 kmTehama County 110 kmLake County 116 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
7.8 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 60 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1675 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 16 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 39.9717, -123.5140. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 60 km (37 mi) N of here earthquakes near Mendocino County
Trinity County, CA 82 km (51 mi) SSW of here earthquakes near Trinity County
Humboldt County, CA 89 km (55 mi) SSE of here earthquakes near Humboldt County
Glenn County, CA 104 km (64 mi) WNW of here earthquakes near Glenn County
Tehama County, CA 110 km (69 mi) W of here earthquakes near Tehama County
Lake County, CA 116 km (72 mi) NW of here earthquakes near Lake 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. 2.3 9km SSE of Laytonville, CA
  2. 2.0 5km NNW of Redway, CA
  3. 1.7 11km SSE of Redway, CA
  4. 2.0 9km WNW of Covelo, CA
  5. 1.6 11km SSE of Redway, CA
  6. 2.7 12km SSE of Redway, CA
  7. 1.8 10km SSE of Redway, CA
  8. 2.0 11km SSE of Redway, CA
  9. 1.9 15km SE of Rockport, CA
  10. 1.7 16km SE of Rockport, CA
  11. 1.8 12km SSE of Redway, CA
  12. 1.7 14km E of Rockport, CA
  13. 2.0 40km SSW of Hayfork, CA
  14. 2.0 19km WNW of Cape Vizcaino, CA
  15. 2.2 4km NNW 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 4,600 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.