QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Rancho Tehama Reserve, CA

No earthquake was likely felt in Rancho Tehama Reserve in the 24 hours to 8:41 pm PST (04:41 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 1.6 earthquake was recorded 24 km (15 mi) west of Rancho Tehama Reserve, CA, at 4:30 am PDT on 22 August 2019 (11:30 UTC), 11 km deep.

USGS: 24km W of Rancho Tehama Reserve, CA

78 km (48 mi) WNW of Chico, CA

4:30 am PDT, Aug 22, 2019 · · 11 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N Tehama County 41 kmGlenn County 49 kmTrinity County 82 kmMendocino County 89 kmColusa County 97 kmLake County 98 kmButte County 99 kmShasta County 102 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
4:30 am PDT on 22 August 2019 ()
Where
24 km (15 mi) west of Rancho Tehama Reserve, CA · earthquakes near Rancho Tehama Reserve
Magnitude
M 1.6 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Tehama County, 41 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2633 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In Rancho Tehama Reserve, 24 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 7.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 · 24 km N 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 39.9837, -122.6813. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Tehama County, CA 41 km (26 mi) ENE earthquakes near Tehama County
Glenn County, CA 49 km (30 mi) SSE earthquakes near Glenn County
Trinity County, CA 82 km (51 mi) NNW earthquakes near Trinity County
Mendocino County, CA 89 km (56 mi) SW earthquakes near Mendocino County
Colusa County, CA 97 km (60 mi) SSE earthquakes near Colusa County
Lake County, CA 98 km (61 mi) S earthquakes near Lake 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. 2.0 11km W of Alder Springs, CA
  2. 2.3 11km W of Alder Springs, CA
  3. 2.0 41km NE of Covelo, CA
  4. 2.0 11km W of Alder Springs, CA
  5. 2.1 26km W of Rancho Tehama Reserve, CA
  6. 2.1 41km NE of Covelo, CA
  7. 2.3 38km NNE of Covelo, CA
  8. 2.9 40km NNE of Covelo, CA
  9. 2.7 41km NNE of Covelo, CA
  10. 2.2 27km WSW of Rancho Tehama Reserve, CA
  11. 2.1 27km SE of Hayfork, CA
  12. 2.2 42km NE of Covelo, CA
  13. 2.4 6km ESE of Red Bluff, CA
  14. 2.1 6km E of Covelo, CA
  15. 2.3 41km NE of Covelo, 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.