QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

3km NE of Fontana, CA

· 14 km deep · released about 890 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 58 kmLos Angeles County 77 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 3.0 (ml)
Depth
14 km below the surface
Felt
432 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Orange County, 58 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2157 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 432 people have reported feeling it to USGS.

How big was it?

This earthquake released about 890 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 380,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 17,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 890 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 34.1117, -117.4347. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 58 km (36 mi) NNE of here earthquakes near Orange County
Los Angeles County, CA 77 km (48 mi) E of here earthquakes near Los Angeles County
San Bernardino County, CA 142 km (88 mi) SW of here earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 1.7 6km E of Calimesa, CA
  2. 1.9 5km SSW of Pinon Hills, CA
  3. 1.5 5km SE of Home Gardens, CA
  4. 1.8 5km SSE of Home Gardens, CA
  5. 1.6 1km ESE of Loma Linda, CA
  6. 1.6 11km WNW of Lake Elsinore, CA
  7. 1.6 3km NNW of Brea, CA
  8. 1.6 9km SSE of Chino, CA
  9. 1.6 8km SSE of Home Gardens, CA
  10. 2.6 1km NNW of Loma Linda, CA
  11. 2.5 8km NNW of Rancho Cucamonga, CA
  12. 1.6 4km SSW of Lytle Creek, CA
  13. 1.6 11km NW of Rancho Cucamonga, CA
  14. 1.7 2km NE of Moreno Valley, CA
  15. 3.2 11km NW of Rancho Cucamonga, 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 130 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.