QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near East Quincy, CA

No earthquake was likely felt in East Quincy in the 24 hours to 1:22 am PST (09:22 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 2.3 earthquake was recorded 23 km (14 mi) east of East Quincy, CA, at 5:38 am PDT on 4 September 2019 (12:38 UTC), 3.0 km deep. 1 person has reported feeling it to USGS.

USGS: 11km NE of Cromberg, CA

80 km (50 mi) NW of Reno, NV

5:38 am PDT, Sep 4, 2019 · · 3.0 km deep · released about 94 lb of TNT

10 km30 km60 km120 km N Plumas County 18 kmSierra County 42 kmNevada County 74 kmLassen County 85 kmButte County 89 kmYuba County 97 kmPlacer County 99 kmStorey County 110 kmCarson City 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
5:38 am PDT on 4 September 2019 ()
Where
23 km (14 mi) east of East Quincy, CA · earthquakes near East Quincy
Magnitude
M 2.3 (md)
Depth
3.0 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Plumas County, 18 km WNW
Nearest mapped fault
Mohawk Valley fault, 9 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 2617 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 20 km (12 mi) from the epicentre. In East Quincy, 23 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: Portola, Quincy.

How big was it?

This earthquake released about 94 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 160,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 10× the energy of this one
  4. This earthquake M 2.3 about 94 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 1,700 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 5.7 2 km NNE of Canyondam, California · 46 km NW of this epicentre
  2. 5.6 6 km NNE of Doyle, California · 50 km ENE of this epicentre
  3. 5.6 5 km NE of Loyalton, California · 45 km SE of this epicentre
  4. 5.3 4 km S of Doyle, California · 44 km E of this epicentre
  5. 5.2 3 km N of Blairsden, California · 15 km S 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 39.9497, -120.6265. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 18 km (11 mi) WNW earthquakes near Plumas County
Sierra County, CA 42 km (26 mi) SSE earthquakes near Sierra County
Nevada County, CA 74 km (46 mi) S earthquakes near Nevada County
Lassen County, CA 85 km (53 mi) N earthquakes near Lassen County
Butte County, CA 89 km (55 mi) WSW earthquakes near Butte County
Yuba County, CA 97 km (61 mi) SW earthquakes near Yuba County

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

Aftershocks so far

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

  1. 1.5 5 km SSW of Sattley, California
  2. 1.8 2km SSW of Canyondam, CA
  3. 1.9 20km SW of Whitehawk, CA
  4. 1.9 3km NNW of Johnsville, CA
  5. 1.6 4km SE of Canyondam, CA
  6. 1.6 4km NE of Canyondam, CA
  7. 1.9 5km NNE of Greenhorn, CA
  8. 1.7 6km NNE of East Quincy, CA
  9. 1.8 7km N of Greenhorn, CA
  10. 1.6 7km NNW of Greenville, CA
  11. 1.5 8km NE of East Shore, CA
  12. 1.5 8km ENE of Hamilton Branch, CA
  13. 1.5 6 km ENE of East Quincy, California
  14. 2.2 14km SW of Whitehawk, CA
  15. 1.6 3km NE 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.