QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

31km SSE of Somes Bar, CA

· 39 km deep · released about 180 lb of TNT

10 km30 km60 km120 km N Trinity County 57 kmHumboldt County 72 kmSiskiyou County 81 kmDel Norte County 89 kmShasta County 113 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 2.5 (md)
Depth
39 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Trinity County, 57 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2917 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 3 people have reported feeling it to USGS.

How big was it?

This earthquake released about 180 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 83,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 59,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.2× the energy of this one
  4. This earthquake M 2.5 about 180 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 41.1393, -123.2905. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 57 km (35 mi) NNW of here earthquakes near Trinity County
Humboldt County, CA 72 km (45 mi) NE of here earthquakes near Humboldt County
Siskiyou County, CA 81 km (50 mi) SW of here earthquakes near Siskiyou County
Del Norte County, CA 89 km (55 mi) SE of here earthquakes near Del Norte County
Shasta County, CA 113 km (70 mi) WNW of here earthquakes near Shasta County
Tehama County, CA 144 km (89 mi) NW of here earthquakes near Tehama County

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

Aftershocks so far

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

  1. 2.3 18km E of Willow Creek, CA
  2. 2.4 12km SE of Weitchpec, CA
  3. 2.3 15km W of Weaverville, CA
  4. 2.3 8km E of Willow Creek, CA
  5. 2.1 24km WNW of Weaverville, CA
  6. 1.8 9km W of Willow Creek, CA
  7. 2.2 20km SE of Willow Creek, CA
  8. 2.2 28km NW of Weaverville, CA
  9. 2.1 16km ESE of Willow Creek, CA
  10. 2.5 27km SSE of Somes Bar, CA
  11. 2.8 15km WNW of Willow Creek, CA
  12. 2.2 3km NW of Willow Creek, CA
  13. 2.5 31km WNW of Weaverville, CA
  14. 2.1 0km NE of Etna, CA
  15. 2.1 24km ESE of Willow Creek, 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.