QuakeIndex

quarry blast · reviewed by a seismologist

M 1.8md

9 km NE of Shasta Lake, CA

· -0.6 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Shasta County 22 kmTehama County 69 kmTrinity County 69 kmSiskiyou County 96 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
-0.6 km below the surface
Felt
no reports yet
Nearest
Shasta County, 22 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 457 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 13 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 40.7443, -122.3030. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Shasta County, CA 22 km (14 mi) W of here earthquakes near Shasta County
Tehama County, CA 69 km (43 mi) N of here earthquakes near Tehama County
Trinity County, CA 69 km (43 mi) E of here earthquakes near Trinity County
Siskiyou County, CA 96 km (60 mi) SSE of here earthquakes near Siskiyou County

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

Aftershocks so far

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

  1. 2.6 18 km NE of French Gulch, CA
  2. 2.8 6 km S of Palo Cedro, CA
  3. 2.1 11 km ENE of Montgomery Creek, CA
  4. 1.7 9 km NE of Shasta Lake, CA
  5. 2.0 9 km WSW of Manton, CA
  6. 1.7 7 km ENE of Millville, CA
  7. 1.6 9 km NE of Shasta Lake, CA
  8. 1.9 2 km W of Millville, CA
  9. 1.9 7 km WSW of Manton, CA
  10. 1.6 20 km W of Big Bend, CA
  11. 1.9 9 km NNE of Shingletown, CA
  12. 1.7 1 km NE of Palo Cedro, CA
  13. 1.7 1 km NE of Palo Cedro, CA
  14. 1.6 13 km NNE of Shingletown, CA
  15. 2.8 9 km WSW of Manton, 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.