QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Redding, CA

No earthquake was likely felt in Redding in the 24 hours to 2:28 am PST (10:28 UTC). The last one was M 2.3, 5 km (3 mi) SW, at 4:06 pm PDT on 4 October 2026, estimated intensity II (weak) in town. Every earthquake near Redding

This page: a magnitude 1.6 earthquake was recorded 17 km (11 mi) east of Redding, CA, at 4:43 am PDT on 27 May 2021 (11:43 UTC), 14 km deep.

USGS: 5km N of Millville, CA

99 km (62 mi) NNW of Chico, CA · 15 km (10 mi) ENE of Redding, CA

4:43 am PDT, May 27, 2021 · · 14 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N Shasta County 21 kmTehama County 53 kmTrinity County 78 kmGlenn County 113 kmSiskiyou County 113 kmButte 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
4:43 am PDT on 27 May 2021 ()
Where
17 km (11 mi) east of Redding, CA · earthquakes near Redding
Magnitude
M 1.6 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Shasta County, 21 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1994 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 Redding, 17 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: Bella Vista, Palo Cedro, Shasta Lake, Anderson, Shasta, Shingletown.

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. 5.1 7km NW of Redding, CA · 19 km W 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 40.6030, -122.1895. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Shasta County, CA 21 km (13 mi) NE earthquakes near Shasta County
Tehama County, CA 53 km (33 mi) S earthquakes near Tehama County
Trinity County, CA 78 km (49 mi) W earthquakes near Trinity County
Glenn County, CA 113 km (70 mi) S earthquakes near Glenn County
Siskiyou County, CA 113 km (70 mi) NNW earthquakes near Siskiyou County
Butte County, CA 116 km (72 mi) SSE earthquakes near Butte County

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

Aftershocks so far

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

  1. 1.6 10km WNW of Montgomery Creek, CA
  2. 1.7 13km W of Round Mountain, CA
  3. 1.9 11km NW of Shasta Lake, CA
  4. 1.7 2km NE of Shasta Lake, CA
  5. 1.6 2km ENE of Shasta Lake, CA
  6. 2.7 6km ENE of Shasta, CA
  7. 1.9 23km N of Shasta Lake, CA
  8. 1.8 6km NNE of Millville, CA
  9. 1.6 15km W of Round Mountain, CA
  10. 1.6 8km NNW of Bella Vista, CA
  11. 1.8 8km NNW of Bella Vista, CA
  12. 1.5 6km NNE of Millville, CA
  13. 1.9 9km ESE of Millville, CA
  14. 1.7 24km N of Shasta Lake, CA
  15. 1.8 11km ESE of Millville, 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.