QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near East Quincy, CA

No earthquake was likely felt in East Quincy in the 24 hours to 6:10 am PST (14:10 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 1.8 earthquake was recorded 18 km (11 mi) east-northeast of East Quincy, CA, at 6:43 pm PDT on 2 April 2018 (01:43 UTC), 14 km deep.

USGS: 10km NNE of Greenhorn, CA

86 km (54 mi) NW of Reno, NV

6:43 pm PDT, Apr 2, 2018 · · 14 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Plumas County 11 kmSierra County 47 kmNevada County 76 kmLassen County 82 kmButte County 85 kmYuba County 97 kmPlacer County 102 kmStorey County 117 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
6:43 pm PDT on 2 April 2018 ()
Where
18 km (11 mi) east-northeast of East Quincy, CA · earthquakes near East Quincy
Magnitude
M 1.8 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Plumas County, 11 km W
Nearest mapped fault
Mohawk Valley fault, 5 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 3138 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 2 km (1 mi) from the epicentre. In East Quincy, 18 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, Greenville.

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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 10,000 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 · 39 km NW of this epicentre
  2. 5.3 4 km S of Doyle, California · 49 km E of this epicentre
  3. 5.2 3 km N of Blairsden, California · 20 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 39.9800, -120.6915. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Plumas County, CA 11 km (7 mi) W earthquakes near Plumas County
Sierra County, CA 47 km (29 mi) SSE earthquakes near Sierra County
Nevada County, CA 76 km (47 mi) S earthquakes near Nevada County
Lassen County, CA 82 km (51 mi) N earthquakes near Lassen County
Butte County, CA 85 km (53 mi) WSW earthquakes near Butte County
Yuba County, CA 97 km (60 mi) SW earthquakes near Yuba County

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

Aftershocks so far

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

  1. 2.1 4km SE of Taylorsville, CA
  2. 1.6 2km SE of Twain, CA
  3. 2.4 4km ESE of Taylorsville, CA
  4. 2.4 2km ESE of Taylorsville, CA
  5. 1.9 4km SE of Taylorsville, CA
  6. 1.6 2 km S of Plumas Eureka, California
  7. 1.9 8km W of La Porte, CA
  8. 2.0 10km WSW of Susanville, CA
  9. 1.7 14km WSW of Susanville, CA
  10. 2.0 9km SW of Susanville, CA
  11. 2.5 10km WSW of Susanville, CA
  12. 2.3 5km E of Johnstonville, CA
  13. 1.6 4 km WSW of Sattley, California
  14. 1.5 4 km WSW of Sattley, California
  15. 1.6 5 km WSW of Sattley, California

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.