QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Rancho Tehama Reserve, CA

No earthquake was likely felt in Rancho Tehama Reserve in the 24 hours to 8:47 pm PST (04:47 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 1.5 earthquake was recorded 36 km (22 mi) west of Rancho Tehama Reserve, CA, at 9:48 pm PST on 26 November 2017 (05:48 UTC), 6.8 km deep.

USGS: 36km W of Rancho Tehama Reserve, CA

89 km (55 mi) WNW of Chico, CA

9:48 pm PST, Nov 26, 2017 · · 6.8 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N Tehama County 52 kmGlenn County 55 kmTrinity County 78 kmMendocino County 81 kmLake County 97 kmColusa County 102 kmShasta County 109 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
9:48 pm PST on 26 November 2017 ()
Where
36 km (22 mi) west of Rancho Tehama Reserve, CA · earthquakes near Rancho Tehama Reserve
Magnitude
M 1.5 (md)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
Tehama County, 52 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3268 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 7 km (4 mi) from the epicentre. In Rancho Tehama Reserve, 36 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 · 26 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 39.9798, -122.8175. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Tehama County, CA 52 km (33 mi) ENE earthquakes near Tehama County
Glenn County, CA 55 km (34 mi) SE earthquakes near Glenn County
Trinity County, CA 78 km (49 mi) NNW earthquakes near Trinity County
Mendocino County, CA 81 km (50 mi) SW earthquakes near Mendocino County
Lake County, CA 97 km (60 mi) S earthquakes near Lake County
Colusa County, CA 102 km (63 mi) SSE earthquakes near Colusa County

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

Aftershocks so far

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

  1. 2.1 42km NNE of Covelo, CA
  2. 1.9 25km SE of Hayfork, CA
  3. 2.5 40km SSE of Hayfork, CA
  4. 2.3 38km SSE of Hayfork, CA
  5. 1.8 38km W of Rancho Tehama Reserve, CA
  6. 1.8 37km WNW of Rancho Tehama Reserve, CA
  7. 2.1 31km NNW of Alder Springs, CA
  8. 1.5 19km NNW of Alder Springs, CA
  9. 2.4 14km W of Red Bluff, CA
  10. 1.8 7km ENE of Covelo, CA
  11. 2.0 37km NNE of Covelo, CA
  12. 2.2 40km NE of Covelo, CA
  13. 1.8 28km NNW of Alder Springs, CA
  14. 1.6 20km N of Covelo, CA
  15. 1.9 35km WNW of Rancho Tehama Reserve, 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.