QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

12 km ENE of Mad River, California

· 29 km deep · released about 25 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 28 kmHumboldt County 54 kmTehama County 104 kmShasta County 116 kmMendocino County 117 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
29 km below the surface
Felt
no reports yet
Nearest
Trinity County, 28 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3300 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 25 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 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 40.4805, -123.3668. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 28 km (18 mi) SW of here earthquakes near Trinity County
Humboldt County, CA 54 km (33 mi) ESE of here earthquakes near Humboldt County
Tehama County, CA 104 km (65 mi) WNW of here earthquakes near Tehama County
Shasta County, CA 116 km (72 mi) WSW of here earthquakes near Shasta County
Mendocino County, CA 117 km (73 mi) N of here earthquakes near Mendocino County
Glenn County, CA 128 km (79 mi) NW of here earthquakes near Glenn County

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

Aftershocks so far

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

  1. 1.6 29km NNE of Redway, CA
  2. 1.7 30km NNE of Redway, CA
  3. 2.1 19km NNE of Redway, CA
  4. 2.7 14km ESE of Willow Creek, CA
  5. 2.0 37km NNE of Redway, CA
  6. 2.5 38km NNE of Redway, CA
  7. 1.9 9km NNW of Hayfork, CA
  8. 3.0 8km NNW of Hayfork, CA
  9. 2.4 16km S of Willow Creek, CA
  10. 1.8 16km S of Willow Creek, CA
  11. 1.8 6km N of Hayfork, CA
  12. 1.9 16km S of Willow Creek, CA
  13. 1.9 17km S of Willow Creek, CA
  14. 1.9 16km S of Willow Creek, CA
  15. 1.9 16km S 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2016-08-28 — it released about 6,700 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.