Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Shasta Lake, CA
No earthquake was likely felt in Shasta Lake in the 24 hours to 12:37 am PST (08:37 UTC). The last one was M 4.4, 117 km (73 mi) SW, at 3:21 pm PDT on 5 August 2026, estimated intensity II (weak) in town; 122 felt reports to USGS. Every earthquake near Shasta Lake
This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) west-southwest of Shasta Lake, CA, at 2:42 pm PDT on 27 April 2021 (21:42 UTC), 17 km deep.
USGS: 3km WSW of Shasta Lake, CA
12 km (7 mi) NNW of Redding, CA · 113 km (70 mi) NNW of Chico, CA
- When
- 2:42 pm PDT on 27 April 2021 ()
- Where
- 3 km (2 mi) west-southwest of Shasta Lake, CA · earthquakes near Shasta Lake
- Magnitude
- M 1.8 (md)
- Depth
- 17 km below the surface
- Felt
- no reports yet
- Nearest
- Shasta County, 32 km ENE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2023 days ago
Earthquake alerts for Shasta Lake, CA
Get a notification in this browser when USGS records an earthquake near Shasta Lake, CA. No account or email needed.
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 Shasta Lake, 3 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: Redding, Shasta, Bella Vista, Palo Cedro, 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 · 5 km S 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 40.6717, -122.4098. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Shasta County, CA | 32 km (20 mi) | ENE | earthquakes near Shasta County |
| Trinity County, CA | 60 km (37 mi) | W | earthquakes near Trinity County |
| Tehama County, CA | 62 km (39 mi) | SSE | earthquakes near Tehama County |
| Siskiyou County, CA | 102 km (64 mi) | N | earthquakes near Siskiyou County |
| Glenn County, CA | 119 km (74 mi) | S | earthquakes near Glenn County |
| Butte County, CA | 131 km (82 mi) | SSE | earthquakes near Butte County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 2.7 6km ENE of Shasta, CA
- 1.9 23km N of Shasta Lake, CA
- 1.8 6km NNE of Millville, CA
- 1.6 15km W of Round Mountain, CA
- 1.6 8km NNW of Bella Vista, CA
- 1.8 8km NNW of Bella Vista, CA
- 1.5 6km NNE of Millville, CA
- 1.9 9km ESE of Millville, CA
- 1.7 24km N of Shasta Lake, CA
- 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
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.