QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

28km NW of Alder Springs, CA

· 7.5 km deep · released about 9.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Glenn County 53 kmMendocino County 65 kmTehama County 66 kmLake County 84 kmTrinity County 90 kmColusa County 96 kmButte County 115 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
7.5 km below the surface
Felt
no reports yet
Nearest
Glenn County, 53 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3174 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 9.6 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 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 39.8537, -122.9245. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Glenn County, CA 53 km (33 mi) WNW of here earthquakes near Glenn County
Mendocino County, CA 65 km (40 mi) NE of here earthquakes near Mendocino County
Tehama County, CA 66 km (41 mi) WSW of here earthquakes near Tehama County
Lake County, CA 84 km (52 mi) N of here earthquakes near Lake County
Trinity County, CA 90 km (56 mi) S of here earthquakes near Trinity County
Colusa County, CA 96 km (59 mi) NW of here earthquakes near Colusa County

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

Aftershocks so far

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

  1. 1.6 7km E of Lake Pillsbury, CA
  2. 2.2 40km NE of Covelo, CA
  3. 1.8 28km NNW of Alder Springs, CA
  4. 1.6 20km N of Covelo, CA
  5. 1.9 35km WNW of Rancho Tehama Reserve, CA
  6. 1.6 28km WSW of Rancho Tehama Reserve, CA
  7. 1.7 42km NW of Rancho Tehama Reserve, CA
  8. 2.3 15km NW of Alder Springs, CA
  9. 2.9 14km NW of Alder Springs, CA
  10. 1.6 18km NW of Lake Pillsbury, CA
  11. 1.5 6km NNE of Lake Pillsbury, CA
  12. 1.7 40km NE of Covelo, CA
  13. 2.4 41km NE of Covelo, CA
  14. 2.0 8km NE of Covelo, CA
  15. 2.0 16km N of Laytonville, 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.