QuakeIndex

quarry blast · reviewed by a seismologist

M 1.8md

22km SW of Mount Hebron, CA

· -1.6 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Siskiyou County 28 kmJackson County 92 kmShasta County 101 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
-1.6 km below the surface
Felt
no reports yet
Nearest
Siskiyou County, 28 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 555 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 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 41.6612, -122.2142. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Siskiyou County, CA 28 km (17 mi) ENE of here earthquakes near Siskiyou County
Jackson County, OR 92 km (57 mi) SSE of here earthquakes near Jackson County
Shasta County, CA 101 km (63 mi) N of here earthquakes near Shasta County
Klamath County, OR 123 km (76 mi) SSW of here earthquakes near Klamath County
Trinity County, CA 136 km (84 mi) NNE of here earthquakes near Trinity County
Josephine County, OR 138 km (86 mi) SE of here earthquakes near Josephine 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. 1.6 4km W of Edgewood, CA
  2. 2.6 23km SW of Mount Hebron, CA
  3. 1.8 9km E of McCloud, CA
  4. 2.6 25km ENE of Hornbrook, CA
  5. 1.8 9km N of McCloud, CA
  6. 1.8 9km N of McCloud, CA
  7. 1.9 10km N of McCloud, CA
  8. 2.4 23km S of Tennant, CA
  9. 1.6 12km N of McCloud, CA
  10. 1.8 9km NNW of McCloud, CA
  11. 1.8 21 km WNW of Dorris, California
  12. 2.1 2km ENE of Dunsmuir, CA
  13. 1.8 22km ENE of Montague, CA
  14. 1.7 10km W of Dorris, CA
  15. 1.5 20 km WNW of Macdoel, California

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.