QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near East Quincy, CA

No earthquake was likely felt in East Quincy in the 24 hours to 9:48 am PST (17:48 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 1.9 earthquake was recorded 16 km (10 mi) east of East Quincy, CA, at 3:09 pm PST on 14 December 2020 (23:09 UTC), less than 1 km deep.

USGS: 5km NE of Greenhorn, CA

85 km (53 mi) WNW of Reno, NV

3:09 pm PST, Dec 14, 2020 · · 0.4 km deep · released about 18 lb of TNT

10 km30 km60 km120 km N Plumas County 12 kmSierra County 43 kmNevada County 71 kmButte County 82 kmLassen County 87 kmYuba County 92 kmPlacer County 97 kmStorey County 116 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
3:09 pm PST on 14 December 2020 ()
Where
16 km (10 mi) east of East Quincy, CA · earthquakes near East Quincy
Magnitude
M 1.9 (md)
Depth
0.4 km below the surface
Felt
no reports yet
Nearest
Plumas County, 12 km WNW
Nearest mapped fault
Mohawk Valley 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 2157 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 14 km (9 mi) from the epicentre. In East Quincy, 16 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, Portola.

How big was it?

This earthquake released about 18 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 840,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 600,000× the energy of this one
  3. Around the size people start to feel M 3.0 53× the energy of this one
  4. This earthquake M 1.9 about 18 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

The largest earthquake within 50 km since 2016 was M 4.5 on 2016-08-04 — about 8,800 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 5.7 2 km NNE of Canyondam, California · 41 km NW of this epicentre
  2. 5.6 5 km NE of Loyalton, California · 50 km ESE of this epicentre
  3. 5.2 3 km N of Blairsden, California · 16 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 39.9380, -120.7095. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 12 km (7 mi) WNW earthquakes near Plumas County
Sierra County, CA 43 km (27 mi) SSE earthquakes near Sierra County
Nevada County, CA 71 km (44 mi) S earthquakes near Nevada County
Butte County, CA 82 km (51 mi) WSW earthquakes near Butte County
Lassen County, CA 87 km (54 mi) N earthquakes near Lassen County
Yuba County, CA 92 km (57 mi) SW earthquakes near Yuba County

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

Aftershocks so far

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

  1. 2.2 4km ENE of Prattville, CA
  2. 2.1 4km SE of Taylorsville, CA
  3. 2.8 11km NNE of Lake Davis, CA
  4. 1.6 3km S of East Shore, CA
  5. 2.1 7km N of Greenhorn, CA
  6. 2.1 1km WNW of Lake Davis, CA
  7. 1.5 6 km SSE of Quincy, California
  8. 2.2 6km SSE of Quincy, CA
  9. 1.5 4km S of Canyondam, CA
  10. 1.5 1km WSW of Canyondam, CA
  11. 2.1 4km SSW of East Shore, CA
  12. 2.3 2km N of Canyondam, CA
  13. 1.8 0 km S of Lake Davis, California
  14. 1.6 3km ENE of Prattville, CA
  15. 1.7 4km NNE of Canyondam, 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.