Earthquake · reviewed by a seismologist
M 1.8md
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 1.8 earthquake was recorded 28 km (17 mi) east-southeast of Redding, CA, at 3:39 pm PST on 18 December 2021 (23:39 UTC), 16 km deep.
USGS: 10km ESE of Millville, CA
87 km (54 mi) NNW of Chico, CA · 25 km (16 mi) ESE of Redding, CA
- When
- 3:39 pm PST on 18 December 2021 ()
- Where
- 28 km (17 mi) east-southeast of Redding, CA · earthquakes near Redding
- Magnitude
- M 1.8 (md)
- Depth
- 16 km below the surface
- Felt
- no reports yet
- Nearest
- Shasta County, 27 km N
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1789 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, 28 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, Anderson.
How big was it?
This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 730,000× the energy of this one
- Around the size people start to feel M 3.0 65× the energy of this one
- This earthquake M 1.8 about 15 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 · 31 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 40.5162, -122.0742. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Shasta County, CA | 27 km (17 mi) | N | earthquakes near Shasta County |
| Tehama County, CA | 45 km (28 mi) | SSW | earthquakes near Tehama County |
| Trinity County, CA | 89 km (55 mi) | W | earthquakes near Trinity County |
| Butte County, CA | 103 km (64 mi) | SSE | earthquakes near Butte County |
| Glenn County, CA | 105 km (65 mi) | SSW | earthquakes near Glenn County |
| Plumas County, CA | 121 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
56 earthquakes have been recorded within 50 km since this one.
- 1.6 8km NE of Shasta Lake, CA
- 2.5 14km ENE of Red Bluff, CA
- 1.6 9km NE of Shasta Lake, CA
- 1.5 18km ESE of Anderson, CA
- 2.6 12km W of Shingletown, CA
- 1.7 24km N of Shasta Lake, CA
- 1.8 6km SW of Shasta Lake, CA
- 1.9 17km WSW of Manton, CA
- 1.7 13km NNE of Shingletown, CA
- 1.6 8km NE of Shasta Lake, CA
- 1.9 13km ESE of Viola, CA
- 1.7 4km SW of Millville, CA
- 1.8 4km NNE of Viola, CA
- 1.8 24km S of Manton, CA
- 1.6 9km NE 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.