QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

24km NW of Alder Springs, CA

· 8.2 km deep · released about 9.3 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Glenn County 50 kmMendocino County 61 kmTehama County 68 kmLake County 79 kmColusa County 91 kmTrinity County 95 kmButte 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 1.7 (md)
Depth
8.2 km below the surface
Felt
no reports yet
Nearest
Glenn County, 50 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3098 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 9.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 100× the energy of this one
  4. This earthquake M 1.7 about 9.3 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 39.8057, -122.9173. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Glenn County, CA 50 km (31 mi) WNW of here earthquakes near Glenn County
Mendocino County, CA 61 km (38 mi) NE of here earthquakes near Mendocino County
Tehama County, CA 68 km (43 mi) WSW of here earthquakes near Tehama County
Lake County, CA 79 km (49 mi) N of here earthquakes near Lake County
Colusa County, CA 91 km (57 mi) NW of here earthquakes near Colusa County
Trinity County, CA 95 km (59 mi) S of here earthquakes near Trinity 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. 1.7 12km SE of Laytonville, CA
  2. 1.6 10km N of Lake Pillsbury, CA
  3. 1.7 5km WNW of Covelo, CA
  4. 1.7 15km N of Alder Springs, CA
  5. 2.0 44km NNE of Covelo, CA
  6. 1.6 14km SE of Laytonville, CA
  7. 2.0 38km S of Hayfork, CA
  8. 2.1 38km S of Hayfork, CA
  9. 2.1 42km NNE of Covelo, CA
  10. 2.5 40km SSE of Hayfork, CA
  11. 2.3 38km SSE of Hayfork, CA
  12. 1.8 38km W of Rancho Tehama Reserve, CA
  13. 1.8 37km WNW of Rancho Tehama Reserve, CA
  14. 2.1 31km NNW of Alder Springs, CA
  15. 1.5 19km NNW of Alder Springs, 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.