QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Rancho Tehama Reserve, CA

No earthquake was likely felt in Rancho Tehama Reserve in the 24 hours to 1:25 pm PST (21:25 UTC). The last one was M 4.0, 74 km (46 mi) SW, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Rancho Tehama Reserve

This page: a magnitude 1.8 earthquake was recorded 38 km (23 mi) west-southwest of Rancho Tehama Reserve, CA, at 8:16 am PDT on 14 August 2024 (15:16 UTC), 5.9 km deep.

USGS: 31 km of Alder Springs, CA

88 km (55 mi) WNW of Chico, CA

8:16 am PDT, Aug 14, 2024 · · 5.9 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Glenn County 51 kmTehama County 55 kmMendocino County 76 kmTrinity County 84 kmLake County 91 kmColusa County 97 kmButte County 108 kmShasta County 114 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
8:16 am PDT on 14 August 2024 ()
Where
38 km (23 mi) west-southwest of Rancho Tehama Reserve, CA · earthquakes near Rancho Tehama Reserve
Magnitude
M 1.8 (md)
Depth
5.9 km below the surface
Felt
no reports yet
Nearest
Glenn County, 51 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 815 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 12 km (7 mi) from the epicentre. In Rancho Tehama Reserve, 38 km away, the estimate is intensity I (not felt). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.5 33 km NW of Rancho Tehama Reserve, California · 32 km NNE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 39.9233, -122.8273. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Glenn County, CA 51 km (32 mi) SE earthquakes near Glenn County
Tehama County, CA 55 km (34 mi) ENE earthquakes near Tehama County
Mendocino County, CA 76 km (47 mi) SW earthquakes near Mendocino County
Trinity County, CA 84 km (52 mi) NNW earthquakes near Trinity County
Lake County, CA 91 km (57 mi) S earthquakes near Lake County
Colusa County, CA 97 km (60 mi) SSE earthquakes near Colusa County

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

Aftershocks so far

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

  1. 1.9 21 km NW of Alder Springs, CA
  2. 1.7 21 km NW of Alder Springs, CA
  3. 2.4 20 km NW of Alder Springs, CA
  4. 1.6 15 km SSE of Covelo, CA
  5. 1.7 20 km NW of Alder Springs, CA
  6. 1.8 20 km NW of Alder Springs, CA
  7. 1.7 21 km NW of Alder Springs, CA
  8. 1.7 10 km N of Lake Pillsbury, CA
  9. 1.9 33 km ENE of Covelo, CA
  10. 2.9 21 km NW of Alder Springs, CA
  11. 2.5 20 km NW of Alder Springs, CA
  12. 2.0 21 km NW of Alder Springs, CA
  13. 2.1 21 km NW of Alder Springs, CA
  14. 1.7 7 km E of Covelo, CA
  15. 2.1 23 km NW 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.