QuakeIndex

quarry blast · reviewed by a seismologist

M 1.8ml

4km SE of Home Gardens, CA

· -0.5 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 33 kmLos Angeles County 81 kmSan Diego County 114 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
-0.5 km below the surface
Felt
no reports yet
Nearest
Orange County, 33 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1620 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 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 33.8568, -117.4900. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 33 km (21 mi) NE of here earthquakes near Orange County
Los Angeles County, CA 81 km (50 mi) ESE of here earthquakes near Los Angeles County
San Diego County, CA 114 km (71 mi) NW of here earthquakes near San Diego County

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

Aftershocks so far

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

  1. 1.5 5km SSW of Lytle Creek, CA
  2. 2.1 7km N of Moreno Valley, CA
  3. 1.5 7km SSE of Home Gardens, CA
  4. 1.5 4km SSW of Redlands, CA
  5. 1.6 6km WSW of Fontana, CA
  6. 2.0 2km ESE of Huntington Beach, CA
  7. 1.5 4km W of Lytle Creek, CA
  8. 2.0 4km NNW of Green Acres, CA
  9. 2.0 12km NNW of Rancho Cucamonga, CA
  10. 1.7 1km NE of Wildomar, CA
  11. 1.9 6km WSW of Yucaipa, CA
  12. 2.2 4km SE of Home Gardens, CA
  13. 1.9 7km SSE of Home Gardens, CA
  14. 1.6 7km SE of Loma Linda, CA
  15. 1.7 7km SE of Loma Linda, 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 7,900 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.