QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Anderson, CA

No earthquake was likely felt in Anderson in the 24 hours to 6:25 am PST (14:25 UTC). The last one was M 2.7, 4 km (2 mi) SSE, at 7:24 pm PDT on 5 August 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Anderson

This page: a magnitude 2.3 earthquake was recorded 15 km (9 mi) east of Anderson, CA, at 1:09 am PDT on 16 March 2021 (08:09 UTC), 21 km deep.

USGS: 15km E of Anderson, CA

79 km (49 mi) NNW of Chico, CA · 26 km (16 mi) SE of Redding, CA

1:09 am PDT, Mar 16, 2021 · · 21 km deep · released about 74 lb of TNT

10 km30 km60 km120 km N Tehama County 35 kmShasta County 38 kmTrinity County 88 kmGlenn County 95 kmButte County 95 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
1:09 am PDT on 16 March 2021 ()
Where
15 km (9 mi) east of Anderson, CA · earthquakes near Anderson
Magnitude
M 2.3 (md)
Depth
21 km below the surface
Felt
no reports yet
Nearest
Tehama County, 35 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2066 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 Anderson, 15 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.

Earthquakes near other towns within 30 km: Palo Cedro, Shingletown, Bella Vista, Redding, Red Bluff.

How big was it?

This earthquake released about 74 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 5.8 200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 140,000× the energy of this one
  3. Around the size people start to feel M 3.0 13× the energy of this one
  4. This earthquake M 2.3 about 74 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. 5.1 7km NW of Redding, CA · 33 km NW 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 40.4265, -122.1210. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Tehama County, CA 35 km (22 mi) SSW earthquakes near Tehama County
Shasta County, CA 38 km (23 mi) N earthquakes near Shasta County
Trinity County, CA 88 km (54 mi) WNW earthquakes near Trinity County
Glenn County, CA 95 km (59 mi) SSW earthquakes near Glenn County
Butte County, CA 95 km (59 mi) SSE earthquakes near Butte County
Plumas County, CA 120 km (75 mi) ESE earthquakes near Plumas 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. 1.7 1km NE of Shasta Lake, CA
  2. 1.7 13km NNE of Shingletown, CA
  3. 1.7 11km NNE of Bella Vista, CA
  4. 1.9 3km NE of Viola, CA
  5. 2.3 6km ENE of Shasta, CA
  6. 1.6 9km NE of Shasta Lake, CA
  7. 1.6 2km WNW of Shasta Lake, CA
  8. 1.8 12km NE of Bella Vista, CA
  9. 2.5 11km NNE of Bella Vista, CA
  10. 2.2 6km NW of Redding, CA
  11. 1.6 16km N of Shingletown, CA
  12. 1.7 4km ENE of Shasta, CA
  13. 2.5 4km ENE of Shasta, CA
  14. 1.8 4km E of Shasta, CA
  15. 1.7 4km NW of Bella Vista, 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.