QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

Earthquake near East Quincy, CA

No earthquake was likely felt in East Quincy in the 24 hours to 2:21 am PST (10:21 UTC). The last one was M 2.3, 6 km (3 mi) N, at 5:11 am PST on 7 November 2026, estimated intensity II (weak) in town. Every earthquake near East Quincy

This page: a magnitude 2.2 earthquake was recorded 14 km (9 mi) northeast of East Quincy, CA, at 10:31 pm PST on 21 December 2018 (06:31 UTC), 3.4 km deep. 2 people have reported feeling it to USGS.

USGS: 5km SE of Taylorsville, CA

98 km (61 mi) NW of Reno, NV

10:31 pm PST, Dec 21, 2018 · · 3.4 km deep · released about 67 lb of TNT

10 km30 km60 km120 km N Plumas County 6 kmSierra County 57 kmLassen County 77 kmButte County 80 kmNevada County 83 kmYuba County 97 kmPlacer County 109 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
10:31 pm PST on 21 December 2018 ()
Where
14 km (9 mi) northeast of East Quincy, CA · earthquakes near East Quincy
Magnitude
M 2.2 (md)
Depth
3.4 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Plumas County, 6 km SSW
Nearest mapped fault
Indian Valley fault, 4 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 2820 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 19 km (12 mi) from the epicentre. In East Quincy, 14 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.

Likely felt in: East Quincy 14 km, intensity II · Greenville 17 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 67 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 230,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 160,000× the energy of this one
  3. Around the size people start to feel M 3.0 14× the energy of this one
  4. This earthquake M 2.2 about 67 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 · 28 km NW of this epicentre
  2. 5.2 3 km N of Blairsden, California · 30 km SSE 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 40.0403, -120.8027. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 6 km (4 mi) SSW earthquakes near Plumas County
Sierra County, CA 57 km (35 mi) SSE earthquakes near Sierra County
Lassen County, CA 77 km (48 mi) NNE earthquakes near Lassen County
Butte County, CA 80 km (50 mi) WSW earthquakes near Butte County
Nevada County, CA 83 km (51 mi) S earthquakes near Nevada County
Yuba County, CA 97 km (61 mi) SSW earthquakes near Yuba County

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

Aftershocks so far

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

  1. 1.7 3km N of Almanor, CA
  2. 2.8 1km WNW of Twain, CA
  3. 2.4 4km ESE of Prattville, CA
  4. 1.6 3km NE of Almanor, CA
  5. 2.3 12km W of La Porte, CA
  6. 2.3 10km ESE of Taylorsville, CA
  7. 1.9 5km WSW of Greenville, CA
  8. 1.5 3 km N of Indian Falls, California
  9. 2.4 3km ESE of Janesville, CA
  10. 1.9 4km SSE of Johnsville, CA
  11. 1.5 4km S of East Shore, CA
  12. 2.3 11km NE of Cromberg, CA
  13. 1.8 1km WNW of Little Grass Valley, CA
  14. 2.2 12km W of La Porte, CA
  15. 1.8 13km W of La Porte, 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.