QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

2 km E of Cromberg, California

· 12 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Plumas County 20 kmSierra County 34 kmNevada County 64 kmButte County 84 kmYuba County 88 kmPlacer County 89 kmLassen County 95 kmStorey County 108 kmCarson City 111 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
Magnitude
M 1.8 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Plumas County, 20 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2706 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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.

Where

Epicentre 39.8635, -120.6575. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Plumas County, CA 20 km (13 mi) SE of here earthquakes near Plumas County
Sierra County, CA 34 km (21 mi) NNW of here earthquakes near Sierra County
Nevada County, CA 64 km (40 mi) N of here earthquakes near Nevada County
Butte County, CA 84 km (52 mi) ENE of here earthquakes near Butte County
Yuba County, CA 88 km (55 mi) NE of here earthquakes near Yuba County
Placer County, CA 89 km (55 mi) N of here earthquakes near Placer County

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

Aftershocks so far

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

  1. 1.9 10km N of Spring Garden, CA
  2. 2.3 5km NNE of Little Grass Valley, CA
  3. 2.1 6km S of Bucks Lake, CA
  4. 2.1 8km W of La Porte, CA
  5. 2.3 22km SW of Whitehawk, CA
  6. 2.8 8km WNW of Lake Davis, CA
  7. 1.5 3km ESE of Canyondam, CA
  8. 1.8 5km ESE of Taylorsville, CA
  9. 1.8 5km ESE of Taylorsville, CA
  10. 1.6 6 km S of Taylorsville, California
  11. 1.6 8km W of La Porte, CA
  12. 1.5 8 km ESE of Milford, California
  13. 1.5 2km SW of Canyondam, CA
  14. 2.8 1km WNW of Twain, CA
  15. 1.5 6 km SSE of Sierraville, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2016-08-04 — it released about 10,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.