QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

27km SSE of Somes Bar, CA

· 39 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Trinity County 60 kmHumboldt County 68 kmDel Norte County 84 kmSiskiyou County 85 kmShasta County 119 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
1 report · strongest reported intensity II
Nearest
Trinity County, 60 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1858 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 170 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 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 41.1497, -123.3650. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 60 km (37 mi) NNW of here earthquakes near Trinity County
Humboldt County, CA 68 km (42 mi) NE of here earthquakes near Humboldt County
Del Norte County, CA 84 km (52 mi) SE of here earthquakes near Del Norte County
Siskiyou County, CA 85 km (53 mi) SW of here earthquakes near Siskiyou County
Shasta County, CA 119 km (74 mi) WNW of here earthquakes near Shasta County
Tehama County, CA 149 km (92 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

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

  1. 2.2 22km SE of Willow Creek, CA
  2. 2.5 8km W of Willow Creek, CA
  3. 2.9 3km SSE of Somes Bar, CA
  4. 2.4 17km E of Willow Creek, CA
  5. 2.9 5km N of Willow Creek, CA
  6. 2.1 29km E of Willow Creek, CA
  7. 4.3 16km WSW of Weitchpec, CA
  8. 3.7 16km WSW of Weitchpec, CA
  9. 2.7 21km ESE of Weitchpec, CA
  10. 2.3 15km E of Willow Creek, CA
  11. 2.4 17km ENE of Willow Creek, CA
  12. 1.8 20km SSE of Willow Creek, CA
  13. 2.1 25km WNW of Weaverville, CA
  14. 2.0 7km W of Willow Creek, CA
  15. 2.4 14km E 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.