QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Palo Cedro, CA

No earthquake was likely felt in Palo Cedro in the 24 hours to 9:15 am PST (17:15 UTC). The last one was M 2.7, 16 km (10 mi) SSW, at 7:24 pm PDT on 5 August 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Palo Cedro

This page: a magnitude 1.7 earthquake was recorded in Palo Cedro, CA, at 2:51 am PDT on 3 September 2021 (09:51 UTC), 18 km deep.

USGS: 2km WSW of Palo Cedro, CA

9 km (6 mi) E of Redding, CA · 96 km (60 mi) NNW of Chico, CA

2:51 am PDT, Sep 3, 2021 · · 18 km deep · released about 9.3 lb of TNT

10 km30 km60 km120 km N Shasta County 29 kmTehama County 48 kmTrinity County 73 kmGlenn County 107 kmButte County 114 kmSiskiyou County 117 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
2:51 am PDT on 3 September 2021 ()
Where
in Palo Cedro, CA · earthquakes near Palo Cedro
Magnitude
M 1.7 (md)
Depth
18 km below the surface
Felt
no reports yet
Nearest
Shasta County, 29 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1890 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. 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, Redding, Anderson, Shasta Lake, Shasta.

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 · 15 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 40.5553, -122.2573. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Shasta County, CA 29 km (18 mi) NE earthquakes near Shasta County
Tehama County, CA 48 km (30 mi) S earthquakes near Tehama County
Trinity County, CA 73 km (45 mi) W earthquakes near Trinity County
Glenn County, CA 107 km (66 mi) S earthquakes near Glenn County
Butte County, CA 114 km (71 mi) SSE earthquakes near Butte County
Siskiyou County, CA 117 km (73 mi) NNW earthquakes near Siskiyou County

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

Aftershocks so far

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

  1. 1.9 13km SSE of Anderson, CA
  2. 1.7 11km NW of Shasta Lake, CA
  3. 1.9 11km NW of Shasta Lake, CA
  4. 1.7 11km WNW of Shasta Lake, CA
  5. 2.4 9km WSW of Shingletown, CA
  6. 1.5 5km N of Millville, CA
  7. 1.6 9km SE of Millville, CA
  8. 1.8 10km ESE of Anderson, CA
  9. 1.7 23km N of Shasta Lake, CA
  10. 1.8 10km ESE of Anderson, CA
  11. 1.8 16km W of Round Mountain, CA
  12. 2.4 3km S of Manton, CA
  13. 1.5 5km N of Millville, CA
  14. 1.5 12km W of Round Mountain, CA
  15. 1.6 10km WNW of Montgomery Creek, 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.