QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

2 km N of Almanor, CA

· 6.3 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Plumas County 40 kmLassen County 71 kmButte County 73 kmTehama County 91 kmSierra County 92 kmShasta County 94 kmYuba County 108 kmNevada County 110 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
6.3 km below the surface
Felt
no reports yet
Nearest
Plumas County, 40 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 961 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 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 40.2347, -121.1728. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Plumas County, CA 40 km (25 mi) NW of here earthquakes near Plumas County
Lassen County, CA 71 km (44 mi) SW of here earthquakes near Lassen County
Butte County, CA 73 km (45 mi) NNE of here earthquakes near Butte County
Tehama County, CA 91 km (56 mi) E of here earthquakes near Tehama County
Sierra County, CA 92 km (57 mi) NW of here earthquakes near Sierra County
Shasta County, CA 94 km (58 mi) SE of here earthquakes near Shasta County

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

Aftershocks so far

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

  1. 2.3 13 km NNE of Chester, CA
  2. 2.0 24 km NNE of Forest Ranch, CA
  3. 1.7 1 km ENE of Prattville, CA
  4. 2.1 0 km SSE of Prattville, CA
  5. 2.1 3 km NE of Almanor, CA
  6. 2.5 1 km ENE of Prattville, CA
  7. 2.6 4 km S of Caribou, CA
  8. 1.7 15 km SSE of Mineral, CA
  9. 2.2 15 km SSE of Mineral, CA
  10. 2.4 1 km N of Almanor, CA
  11. 2.1 4 km WNW of Canyondam, CA
  12. 2.6 4 km WNW of Canyondam, CA
  13. 2.1 3 km NNE of Prattville, CA
  14. 2.3 3 km E of Prattville, CA
  15. 1.9 3 km WSW of Chester, 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 5.5 on 2023-05-11 — it released about 340,000 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.