QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Greenville, CA

No earthquake was likely felt in Greenville in the 24 hours to 6:29 am PST (14:29 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 1.6 earthquake was recorded 11 km (7 mi) west of Greenville, CA, at 2:08 pm PST on 20 February 2021 (22:08 UTC), 7.8 km deep.

USGS: 3km S of Canyondam, CA

2:08 pm PST, Feb 20, 2021 · · 7.8 km deep · released about 8.1 lb of TNT

10 km30 km60 km120 km N Plumas County 27 kmButte County 70 kmLassen County 74 kmSierra County 79 kmNevada County 98 kmTehama County 98 kmYuba County 100 kmShasta County 107 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
2:08 pm PST on 20 February 2021 ()
Where
11 km (7 mi) west of Greenville, CA · earthquakes near Greenville
Magnitude
M 1.6 (md)
Depth
7.8 km below the surface
Felt
no reports yet
Nearest
Plumas County, 27 km SE
Nearest mapped fault
Almanor fault, 2 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 2083 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 8 km (5 mi) from the epicentre. In Greenville, 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.

Earthquakes near other towns within 30 km: Westwood, Chester, Quincy, East Quincy.

How big was it?

This earthquake released about 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 8.1 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 · 6 km NNE of this epicentre
  2. 5.5 15 km NE of Mineral, California · 48 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 40.1432, -121.0763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 27 km (17 mi) SE earthquakes near Plumas County
Butte County, CA 70 km (43 mi) SW earthquakes near Butte County
Lassen County, CA 74 km (46 mi) NNE earthquakes near Lassen County
Sierra County, CA 79 km (49 mi) SE earthquakes near Sierra County
Nevada County, CA 98 km (61 mi) SSE earthquakes near Nevada County
Tehama County, CA 98 km (61 mi) W earthquakes near Tehama County

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

Aftershocks so far

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

  1. 2.7 5km ENE of East Quincy, CA
  2. 1.8 3km NNE of Chester, CA
  3. 2.1 3km NNE of Chester, CA
  4. 2.1 6km SW of Cromberg, CA
  5. 1.9 13km WSW of Almanor, CA
  6. 1.9 9km WSW of Chester, CA
  7. 2.0 9km WSW of Chester, CA
  8. 2.2 4km ENE of Prattville, CA
  9. 1.9 10km WSW of Chester, CA
  10. 2.1 4km SE of Taylorsville, CA
  11. 1.6 3km S of East Shore, CA
  12. 1.9 9km W of Caribou, CA
  13. 2.1 7km N of Greenhorn, CA
  14. 1.6 14km NE of Mineral, CA
  15. 1.5 11km SW of Chester, 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.