QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

10 km WSW of Fall River Mills, CA

· 16 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Shasta County 47 kmLassen County 82 kmModoc County 99 kmSiskiyou County 108 kmTehama County 109 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
16 km below the surface
Felt
no reports yet
Nearest
Shasta County, 47 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1057 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 40.9560, -121.5455. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Shasta County, CA 47 km (29 mi) ENE of here earthquakes near Shasta County
Lassen County, CA 82 km (51 mi) WNW of here earthquakes near Lassen County
Modoc County, CA 99 km (61 mi) SW of here earthquakes near Modoc County
Siskiyou County, CA 108 km (67 mi) SE of here earthquakes near Siskiyou County
Tehama County, CA 109 km (68 mi) NNE of here earthquakes near Tehama County
Plumas County, CA 123 km (77 mi) NNW of here earthquakes near Plumas County

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

Aftershocks so far

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

  1. 1.6 8 km NNE of Viola, CA
  2. 1.7 7 km NNE of Viola, CA
  3. 1.9 17 km N of McArthur, CA
  4. 1.5 13 km NNE of Viola, CA
  5. 1.7 28 km E of Viola, CA
  6. 1.7 16 km S of Round Mountain, CA
  7. 1.7 16 km S of Round Mountain, CA
  8. 1.8 12 km NE of Shingletown, CA
  9. 2.9 23 km ENE of Viola, CA
  10. 1.5 23 km ENE of Viola, CA
  11. 1.9 23 km ENE of Viola, CA
  12. 1.6 25 km ENE of Viola, CA
  13. 1.9 6 km SE of Burney, CA
  14. 1.7 7 km WSW of Round Mountain, CA
  15. 2.4 4 km W of McArthur, 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 5.0 on 2023-09-08 — it released about 63,000 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.