QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Greenville, CA

No earthquake was likely felt in Greenville in the 24 hours to 12:21 pm PST (20:21 UTC). The last one was M 2.3, 18 km (11 mi) SSE, at 5:11 am PST on 7 November 2026, estimated intensity II (weak) in town. Every earthquake near Greenville

This page: a magnitude 1.7 earthquake was recorded 12 km (7 mi) west-southwest of Greenville, CA, at 2:49 pm PDT on 21 April 2023 (21:49 UTC), 5.7 km deep.

USGS: 7 km S of Canyondam, California

2:49 pm PDT, Apr 21, 2023 · · 5.7 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Plumas County 25 kmButte County 66 kmSierra County 75 kmLassen County 78 kmNevada County 93 kmYuba County 95 kmTehama County 98 kmShasta County 110 kmPlacer County 120 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
2:49 pm PDT on 21 April 2023 ()
Where
12 km (7 mi) west-southwest of Greenville, CA · earthquakes near Greenville
Magnitude
M 1.7 (ml)
Depth
5.7 km below the surface
Felt
no reports yet
Nearest
Plumas County, 25 km ESE
Nearest mapped fault
Almanor fault, 6 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 1301 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 Greenville, 12 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: Quincy, Westwood, East Quincy, Chester.

How big was it?

This earthquake released about 11 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 1,400,000× 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 89× the energy of this one
  4. This earthquake M 1.7 about 11 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. 5.7 2 km NNE of Canyondam, California · 10 km N 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 40.1021, -121.0788. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 25 km (15 mi) ESE earthquakes near Plumas County
Butte County, CA 66 km (41 mi) SW earthquakes near Butte County
Sierra County, CA 75 km (47 mi) SE earthquakes near Sierra County
Lassen County, CA 78 km (49 mi) NNE earthquakes near Lassen County
Nevada County, CA 93 km (58 mi) SSE earthquakes near Nevada County
Yuba County, CA 95 km (59 mi) SSW earthquakes near Yuba 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. 2.3 2km N of Prattville, CA
  2. 2.9 4km NW of Canyondam, CA
  3. 2.3 2km ESE of Prattville, CA
  4. 2.0 3km NNE of Almanor, CA
  5. 2.9 1km N of Prattville, CA
  6. 2.4 4km NW of Canyondam, CA
  7. 3.1 3km NNW of Canyondam, CA
  8. 2.8 4km ESE of Prattville, CA
  9. 2.3 6km N of Caribou, CA
  10. 2.7 3km ESE of Prattville, CA
  11. 2.2 2km NNE of Prattville, CA
  12. 1.9 4km NNE of Almanor, CA
  13. 2.4 4km S of East Shore, CA
  14. 2.2 3km NE of Prattville, CA
  15. 2.2 4km ENE of Prattville, 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.