QuakeIndex

quarry blast · reviewed by a seismologist

M 1.8ml

5km NE of Bradbury, CA

· -0.8 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 31 kmOrange County 58 kmVentura County 113 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
-0.8 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 31 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2225 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 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.

Where

Epicentre 34.1800, -117.9275. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Los Angeles County, CA 31 km (19 mi) E of here earthquakes near Los Angeles County
Orange County, CA 58 km (36 mi) NNW of here earthquakes near Orange County
Ventura County, CA 113 km (70 mi) E of here earthquakes near Ventura County

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

Aftershocks so far

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

  1. 1.7 7km SSE of Littlerock, CA
  2. 1.6 8km SW of Lytle Creek, CA
  3. 1.9 4km SSW of San Dimas, CA
  4. 2.1 6km SSW of Pearblossom, CA
  5. 1.5 1km NNW of La Habra, CA
  6. 2.1 2km W of Devore, CA
  7. 1.7 4km SSW of Pinon Hills, CA
  8. 2.3 3km S of Yorba Linda, CA
  9. 1.9 5km SSW of Pinon Hills, CA
  10. 1.6 4km W of South El Monte, CA
  11. 1.6 3km NNW of Brea, CA
  12. 1.6 9km SSE of Chino, CA
  13. 1.5 3km SW of La Mirada, CA
  14. 2.5 8km NNW of Rancho Cucamonga, CA
  15. 1.6 4km SSW of Lytle Creek, 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 4.4 on 2018-08-29 — it released about 7,200 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.