QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

14km WNW of Alder Springs, CA

· 12 km deep · released about 19 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Glenn County 42 kmMendocino County 57 kmLake County 67 kmTehama County 72 kmColusa County 80 kmTrinity County 107 kmButte County 109 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 1.9 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Glenn County, 42 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1547 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 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 790,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 560,000× the energy of this one
  3. Around the size people start to feel M 3.0 50× the energy of this one
  4. This earthquake M 1.9 about 19 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 39.6995, -122.8733. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Glenn County, CA 42 km (26 mi) WNW of here earthquakes near Glenn County
Mendocino County, CA 57 km (36 mi) ENE of here earthquakes near Mendocino County
Lake County, CA 67 km (41 mi) N of here earthquakes near Lake County
Tehama County, CA 72 km (45 mi) SW of here earthquakes near Tehama County
Colusa County, CA 80 km (50 mi) NW of here earthquakes near Colusa County
Trinity County, CA 107 km (67 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

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

  1. 1.7 12km N of Brooktrails, CA
  2. 1.7 14km N of Lake Pillsbury, CA
  3. 1.6 18km NW of Lake Pillsbury, CA
  4. 1.8 9km NNW of Lake Pillsbury, CA
  5. 1.6 9km E of Willits, CA
  6. 1.8 17km NNE of Upper Lake, CA
  7. 1.5 8km NE of Brooktrails, CA
  8. 1.7 12km W of Lake Pillsbury, CA
  9. 1.8 8km NE of Brooktrails, CA
  10. 2.5 5km E of Covelo, CA
  11. 2.0 32km WNW of Rancho Tehama Reserve, CA
  12. 1.6 5km E of Covelo, CA
  13. 1.8 5km ENE of Covelo, CA
  14. 2.8 5km E of Covelo, CA
  15. 1.7 7km E of Lake Pillsbury, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.1 on 2016-08-10 — it released about 68,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.