QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Shingletown, CA

No earthquake was likely felt in Shingletown in the 24 hours to 6:08 am PST (14:08 UTC). The last one was M 5.6, 170 km (106 mi) SW, at 8:10 am PDT on 24 June 2026, estimated intensity III (weak) in town; 5,311 felt reports to USGS. Every earthquake near Shingletown

This page: a magnitude 2.3 earthquake was recorded 27 km (17 mi) east of Shingletown, CA, at 8:30 pm PDT on 11 April 2021 (03:30 UTC), 2.7 km deep.

USGS: 9km ENE of Viola, CA

89 km (55 mi) NNE of Chico, CA

8:30 pm PDT, Apr 11, 2021 · · 2.7 km deep · released about 82 lb of TNT

10 km30 km60 km120 km N Shasta County 47 kmTehama County 72 kmLassen County 83 kmPlumas County 88 kmButte County 97 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
8:30 pm PDT on 11 April 2021 ()
Where
27 km (17 mi) east of Shingletown, CA · earthquakes near Shingletown
Magnitude
M 2.3 (md)
Depth
2.7 km below the surface
Felt
no reports yet
Nearest
Shasta County, 47 km WNW
Nearest mapped fault
Hat Creek fault, 19 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2040 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 19 km (12 mi) from the epicentre. In Shingletown, 27 km away, the estimate is intensity II (weak). 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 82 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 82 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 15 km NE of Mineral, California · 13 km SE 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 40.5395, -121.5728. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Shasta County, CA 47 km (29 mi) WNW earthquakes near Shasta County
Tehama County, CA 72 km (45 mi) SW earthquakes near Tehama County
Lassen County, CA 83 km (51 mi) ENE earthquakes near Lassen County
Plumas County, CA 88 km (55 mi) SE earthquakes near Plumas County
Butte County, CA 97 km (60 mi) S earthquakes near Butte County
Glenn County, CA 126 km (78 mi) SW earthquakes near Glenn County

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

Aftershocks so far

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

  1. 2.1 3km NNE of Chester, CA
  2. 1.8 36km SE of Fall River Mills, CA
  3. 1.8 3km NNE of Chester, CA
  4. 2.1 3km NNE of Chester, CA
  5. 2.1 14km ESE of Viola, CA
  6. 2.1 13km NE of Montgomery Creek, CA
  7. 1.9 13km WSW of Almanor, CA
  8. 1.6 16km N of Shingletown, CA
  9. 2.1 10km NNW of Burney, CA
  10. 1.9 9km WSW of Chester, CA
  11. 1.5 12km ESE of Viola, CA
  12. 2.0 9km WSW of Chester, CA
  13. 1.5 12km ESE of Viola, CA
  14. 1.9 10km WSW of Chester, CA
  15. 1.6 15km NNE of Mineral, 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.