QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Shasta Lake, CA

No earthquake was likely felt in Shasta Lake in the 24 hours to 11:37 pm PST (07:37 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 1.7 earthquake was recorded 29 km (18 mi) north of Shasta Lake, CA, at 9:15 pm PDT on 8 May 2021 (04:15 UTC), 14 km deep.

USGS: 29km N of Shasta Lake, CA

41 km (26 mi) N of Redding, CA · 141 km (87 mi) NNW of Chico, CA

9:15 pm PDT, May 8, 2021 · · 14 km deep · released about 9.3 lb of TNT

Every earthquake near Shasta Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Shasta County 37 kmTrinity County 67 kmSiskiyou County 73 kmTehama County 92 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
9:15 pm PDT on 8 May 2021 ()
Where
29 km (18 mi) north of Shasta Lake, CA · earthquakes near Shasta Lake
Magnitude
M 1.7 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Shasta County, 37 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2013 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 Shasta Lake, 29 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.

How big was it?

This earthquake released about 9.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 100× the energy of this one
  4. This earthquake M 1.7 about 9.3 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 · 35 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 40.9397, -122.4168. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Shasta County, CA 37 km (23 mi) ESE earthquakes near Shasta County
Trinity County, CA 67 km (42 mi) WSW earthquakes near Trinity County
Siskiyou County, CA 73 km (45 mi) N earthquakes near Siskiyou County
Tehama County, CA 92 km (57 mi) S earthquakes near Tehama County

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

Aftershocks so far

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

  1. 1.7 24km N of Shasta Lake, CA
  2. 1.7 27km N of Shasta Lake, CA
  3. 1.8 23km N of Shasta Lake, CA
  4. 1.7 1km NE of Shasta Lake, CA
  5. 1.7 11km NNE of Bella Vista, CA
  6. 2.3 6km ENE of Shasta, CA
  7. 1.6 9km NE of Shasta Lake, CA
  8. 1.6 2km WNW of Shasta Lake, CA
  9. 1.8 12km NE of Bella Vista, CA
  10. 2.5 11km NNE of Bella Vista, CA
  11. 1.9 16km SSE of McCloud, CA
  12. 2.2 6km NW of Redding, CA
  13. 1.7 4km ENE of Shasta, CA
  14. 1.6 12km SE of Dunsmuir, CA
  15. 2.5 13km SE of Dunsmuir, 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.