QuakeIndex

Earthquake · automatic estimate, may change

M 2.4md

12 km SSW of Johnsville, CA

· 27 km deep · released about 110 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sierra County 24 kmPlumas County 35 kmNevada County 43 kmYuba County 68 kmPlacer County 69 kmButte County 72 kmEl Dorado County 102 kmCarson City 105 kmSutter County 109 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 2.4 (md)
Depth
27 km below the surface
Felt
no reports yet
Nearest
Sierra County, 24 km ESE
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 235 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 110 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 140,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 99,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.8× the energy of this one
  4. This earthquake M 2.4 about 110 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 39.6858, -120.7577. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Sierra County, CA 24 km (15 mi) WNW of here earthquakes near Sierra County
Plumas County, CA 35 km (21 mi) S of here earthquakes near Plumas County
Nevada County, CA 43 km (27 mi) N of here earthquakes near Nevada County
Yuba County, CA 68 km (42 mi) NE of here earthquakes near Yuba County
Placer County, CA 69 km (43 mi) N of here earthquakes near Placer County
Butte County, CA 72 km (45 mi) E of here earthquakes near Butte County

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

Aftershocks so far

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

  1. 2.3 2 km ENE of Keddie, CA
  2. 2.2 9 km S of Johnsville, CA
  3. 2.1 7 km NE of Lake Davis, CA
  4. 2.0 6 km E of Challenge-Brownsville, CA
  5. 2.1 8 km WNW of La Porte, CA
  6. 2.6 8 km NE of Lake Davis, CA
  7. 2.1 7 km ESE of Challenge-Brownsville, CA
  8. 2.3 8 km NE of Lake Davis, CA
  9. 2.2 8 km NE of Lake Davis, CA
  10. 2.0 5 km SSW of Cromberg, CA
  11. 3.0 4 km WSW of Johnsville, CA
  12. 2.4 5 km NW of Johnsville, CA
  13. 2.1 8 km NE of Lake Davis, CA
  14. 2.2 8 km NE of Lake Davis, CA
  15. 2.1 16 km SE of Whitehawk, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.7 on 2021-05-07 — it released about 2,600 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.