QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

1km NNW of Spring Garden, CA

· 6.8 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Plumas County 9 kmSierra County 44 kmNevada County 69 kmButte County 74 kmYuba County 86 kmLassen County 90 kmPlacer County 95 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 (md)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
Plumas County, 9 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3160 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 39.9153, -120.7993. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Plumas County, CA 9 km (5 mi) SSE of here earthquakes near Plumas County
Sierra County, CA 44 km (28 mi) NNW of here earthquakes near Sierra County
Nevada County, CA 69 km (43 mi) N of here earthquakes near Nevada County
Butte County, CA 74 km (46 mi) ENE of here earthquakes near Butte County
Yuba County, CA 86 km (53 mi) NNE of here earthquakes near Yuba County
Lassen County, CA 90 km (56 mi) S of here earthquakes near Lassen 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. 2.9 6km SW of Almanor, CA
  2. 1.6 20km S of Honey Lake, CA
  3. 1.7 2km NE of Almanor, CA
  4. 1.7 4km WSW of Canyondam, CA
  5. 1.6 7km ESE of East Shore, CA
  6. 2.2 2km NNE of Indian Falls, CA
  7. 2.9 18km SW of Whitehawk, CA
  8. 1.5 6 km SW of Canyondam, California
  9. 2.2 3km SE of Belden, CA
  10. 1.5 3 km SSW of Greenville, California
  11. 2.2 12km WNW of Lake Davis, CA
  12. 1.9 3km W of Delleker, CA
  13. 2.9 3km NNE of Almanor, CA
  14. 2.3 4km NNE of Almanor, CA
  15. 1.8 5km SSW of Cromberg, 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.