QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Chester, CA

No earthquake was likely felt in Chester in the 24 hours to 5:35 pm PST (01:35 UTC). The last one was M 2.1, 17 km (11 mi) SE, at 8:09 am PDT on 29 October 2026, estimated intensity II (weak) in town. Every earthquake near Chester

This page: a magnitude 1.7 earthquake was recorded 11 km (7 mi) west-northwest of Chester, CA, at 4:33 pm PDT on 24 September 2022 (23:33 UTC), 5.8 km deep.

USGS: 11km WNW of Chester, CA

76 km (47 mi) NNE of Chico, CA

4:33 pm PDT, Sep 24, 2022 · · 5.8 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Plumas County 60 kmShasta County 74 kmLassen County 75 kmTehama County 78 kmButte County 78 kmSierra County 111 kmYuba County 119 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
4:33 pm PDT on 24 September 2022 ()
Where
11 km (7 mi) west-northwest of Chester, CA · earthquakes near Chester
Magnitude
M 1.7 (md)
Depth
5.8 km below the surface
Felt
no reports yet
Nearest
Plumas County, 60 km SE
Nearest mapped fault
Almanor fault, 11 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1510 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. In Chester, 11 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.

How big was it?

This earthquake released about 10 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 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 2 earthquakes of M5 or more within 50 km:

  1. 5.7 2 km NNE of Canyondam, California · 30 km ESE of this epicentre
  2. 5.5 15 km NE of Mineral, California · 15 km NW 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 40.3420, -121.3580. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 60 km (37 mi) SE earthquakes near Plumas County
Shasta County, CA 74 km (46 mi) NW earthquakes near Shasta County
Lassen County, CA 75 km (47 mi) NE earthquakes near Lassen County
Tehama County, CA 78 km (48 mi) WSW earthquakes near Tehama County
Butte County, CA 78 km (49 mi) SSW earthquakes near Butte County
Sierra County, CA 111 km (69 mi) SE earthquakes near Sierra 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. 2.4 3km E of Prattville, CA
  2. 2.6 3km SSW of East Shore, CA
  3. 2.6 4km E of Prattville, CA
  4. 2.4 4km SW of East Shore, CA
  5. 2.8 2km NNE of Almanor, CA
  6. 5.5 Lake Almanor Earthquake
  7. 2.4 12km S of Manton, CA
  8. 2.3 2km ESE of Canyondam, CA
  9. 1.5 4 km SSW of Greenville, California
  10. 1.8 14km NE of Mineral, CA
  11. 1.9 4km W of Mineral, CA
  12. 1.5 4 km W of Greenville, California
  13. 1.7 7 km S of Canyondam, California
  14. 2.6 13km S of Manton, CA
  15. 2.0 12km SSW of Manton, 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.