QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Red Bluff, CA

No earthquake was likely felt in Red Bluff in the 24 hours to 6:55 pm PST (02:55 UTC). The last one was M 4.0, 97 km (60 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 Red Bluff

This page: a magnitude 1.9 earthquake was recorded 48 km (30 mi) west of Red Bluff, CA, at 4:11 pm PDT on 18 June 2018 (23:11 UTC), 8.7 km deep.

USGS: 35km WNW of Rancho Tehama Reserve, CA

92 km (57 mi) WNW of Chico, CA

4:11 pm PDT, Jun 18, 2018 · · 8.7 km deep · released about 25 lb of TNT

10 km30 km60 km120 km N Tehama County 48 kmTrinity County 65 kmGlenn County 66 kmMendocino County 94 kmShasta County 96 kmLake County 112 kmButte County 113 kmColusa County 114 kmHumboldt County 116 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
4:11 pm PDT on 18 June 2018 ()
Where
48 km (30 mi) west of Red Bluff, CA · earthquakes near Red Bluff
Magnitude
M 1.9 (md)
Depth
8.7 km below the surface
Felt
no reports yet
Nearest
Tehama County, 48 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3068 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 13 km (8 mi) from the epicentre. In Red Bluff, 48 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 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.

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 · 12 km NE 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 40.1118, -122.7965. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Tehama County, CA 48 km (30 mi) E earthquakes near Tehama County
Trinity County, CA 65 km (41 mi) NNW earthquakes near Trinity County
Glenn County, CA 66 km (41 mi) SSE earthquakes near Glenn County
Mendocino County, CA 94 km (58 mi) SW earthquakes near Mendocino County
Shasta County, CA 96 km (60 mi) NE earthquakes near Shasta County
Lake County, CA 112 km (69 mi) S earthquakes near Lake County

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

Aftershocks so far

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

  1. 2.7 37km SSE of Hayfork, CA
  2. 1.5 41km NE of Covelo, CA
  3. 1.9 21km W of Rancho Tehama Reserve, CA
  4. 1.7 8km ENE of Covelo, CA
  5. 1.9 19km NNW of Alder Springs, CA
  6. 1.8 20km NNW of Alder Springs, CA
  7. 2.4 14km NW of Alder Springs, CA
  8. 1.8 23km WNW of Alder Springs, CA
  9. 1.8 16km NW of Alder Springs, CA
  10. 1.6 24km W of Rancho Tehama Reserve, CA
  11. 2.6 17km SSE of Hayfork, CA
  12. 2.3 15km NNE of Alder Springs, CA
  13. 2.0 14km NNE of Alder Springs, CA
  14. 2.1 12km N of Alder Springs, CA
  15. 2.0 42km N 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.