Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Redding, CA
No earthquake was likely felt in Redding in the 24 hours to 2:24 am PST (10:24 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 26 km (16 mi) east of Redding, CA, at 8:03 am PDT on 20 May 2021 (15:03 UTC), 11 km deep.
USGS: 9km E of Millville, CA
92 km (57 mi) NNW of Chico, CA · 24 km (15 mi) E of Redding, CA
- When
- 8:03 am PDT on 20 May 2021 ()
- Where
- 26 km (16 mi) east of Redding, CA · earthquakes near Redding
- Magnitude
- M 1.6 (md)
- Depth
- 11 km below the surface
- Felt
- no reports yet
- Nearest
- Shasta County, 23 km N
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1994 days ago
Earthquake alerts for Redding, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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, 26 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.
Earthquakes near other towns within 30 km: Palo Cedro, Bella Vista, Shingletown, Anderson, Shasta Lake.
How big was it?
This earthquake released about 6.6 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.
- Mineral, Virginia 2011 M 5.8 2,300,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
- Around the size people start to feel M 3.0 140× the energy of this one
- This earthquake M 1.6 about 6.6 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:
- 5.1 7km NW of Redding, CA · 29 km WNW 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 40.5585, -122.0830. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Shasta County, CA | 23 km (14 mi) | N | earthquakes near Shasta County |
| Tehama County, CA | 50 km (31 mi) | SSW | earthquakes near Tehama County |
| Trinity County, CA | 88 km (54 mi) | W | earthquakes near Trinity County |
| Butte County, CA | 107 km (67 mi) | SSE | earthquakes near Butte County |
| Glenn County, CA | 110 km (68 mi) | SSW | earthquakes near Glenn County |
| Siskiyou County, CA | 121 km (75 mi) | NNW | earthquakes near Siskiyou County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
51 earthquakes have been recorded within 50 km since this one.
- 1.8 11km ESE of Millville, CA
- 1.6 7km WSW of Shingletown, CA
- 2.3 9km WSW of Shingletown, CA
- 1.8 10km ESE of Millville, CA
- 1.7 27km N of Shasta Lake, CA
- 1.8 23km N of Shasta Lake, CA
- 1.7 1km NE of Shasta Lake, CA
- 1.7 13km NNE of Shingletown, CA
- 1.9 9km E of Montgomery Creek, CA
- 1.7 11km NNE of Bella Vista, CA
- 1.6 12km N of Mineral, CA
- 1.9 3km NE of Viola, CA
- 2.3 6km ENE of Shasta, CA
- 1.6 9km NE of Shasta Lake, CA
- 1.6 2km WNW of Shasta Lake, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.