QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

6km SE of Viola, CA

· 17 km deep · released about 400 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Shasta County 47 kmTehama County 65 kmPlumas County 87 kmLassen County 88 kmButte County 91 kmGlenn County 118 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 2.8 (md)
Depth
17 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Shasta County, 47 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1380 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 400 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 38,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 27,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.4× the energy of this one
  4. This earthquake M 2.8 about 400 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 40.4825, -121.6190. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Shasta County, CA 47 km (29 mi) SE of here earthquakes near Shasta County
Tehama County, CA 65 km (41 mi) NE of here earthquakes near Tehama County
Plumas County, CA 87 km (54 mi) NW of here earthquakes near Plumas County
Lassen County, CA 88 km (55 mi) WSW of here earthquakes near Lassen County
Butte County, CA 91 km (56 mi) N of here earthquakes near Butte County
Glenn County, CA 118 km (74 mi) NE of here earthquakes near Glenn 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. 2.7 2km NE of Almanor, CA
  2. 2.3 2km N of Prattville, CA
  3. 1.9 4km NNE of Prattville, CA
  4. 2.3 2km NE of Almanor, CA
  5. 2.4 2km NE of Almanor, CA
  6. 2.8 2km NNE of Prattville, CA
  7. 3.0 1km N of Prattville, CA
  8. 2.5 1km ENE of Almanor, CA
  9. 2.8 2km NNE of Almanor, CA
  10. 2.4 12km S of Manton, CA
  11. 1.8 14km NE of Mineral, CA
  12. 1.9 4km W of Mineral, CA
  13. 1.8 5km NNE of Montgomery Creek, CA
  14. 2.6 13km S of Manton, CA
  15. 1.8 18km SSE of Round Mountain, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.