QuakeIndex

quarry blast · reviewed by a seismologist

M 1.9md

8km WNW of Ione, CA

· -0.6 km deep · released about 22 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sacramento County 30 kmAmador County 32 kmCalaveras County 45 kmSan Joaquin County 54 kmEl Dorado County 61 kmPlacer County 80 kmSolano County 82 kmYolo County 84 kmStanislaus County 91 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 1.9 (md)
Depth
-0.6 km below the surface
Felt
no reports yet
Nearest
Sacramento County, 30 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1511 days ago

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

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 22 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 680,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 480,000× the energy of this one
  3. Around the size people start to feel M 3.0 43× the energy of this one
  4. This earthquake M 1.9 about 22 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 38.3803, -121.0120. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Sacramento County, CA 30 km (19 mi) ESE of here earthquakes near Sacramento County
Amador County, CA 32 km (20 mi) WSW of here earthquakes near Amador County
Calaveras County, CA 45 km (28 mi) WNW of here earthquakes near Calaveras County
San Joaquin County, CA 54 km (34 mi) NNE of here earthquakes near San Joaquin County
El Dorado County, CA 61 km (38 mi) SW of here earthquakes near El Dorado County
Placer County, CA 80 km (50 mi) SSW of here earthquakes near Placer County

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

Aftershocks so far

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

  1. 1.8 1 km WSW of Granite Bay, CA
  2. 1.8 6 km WNW of Ione, CA
  3. 2.1 2 km WSW of Granite Bay, CA
  4. 2.6 2 km NW of Granite Bay, 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.