QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

4km SSE of Charter Oak, CA

· 12 km deep · released about 140 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 42 kmOrange County 45 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 2.5 (ml)
Depth
12 km below the surface
Felt
24 reports · strongest reported intensity III
Nearest
Los Angeles County, 42 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1671 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 24 people have reported feeling it to USGS.

How big was it?

This earthquake released about 140 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 110,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 75,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.7× the energy of this one
  4. This earthquake M 2.5 about 140 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 34.0755, -117.8263. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Los Angeles County, CA 42 km (26 mi) ESE of here earthquakes near Los Angeles County
Orange County, CA 45 km (28 mi) N of here earthquakes near Orange County
San Diego County, CA 152 km (95 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

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

  1. 3.3 6km E of Ontario, CA
  2. 1.6 5km SE of Home Gardens, CA
  3. 1.7 5km NNE of Fontana, CA
  4. 1.9 6km SSE of Lytle Creek, CA
  5. 1.7 4km SSE of Home Gardens, CA
  6. 2.2 7km SSW of Littlerock, CA
  7. 1.8 3km SSW of San Bernardino, CA
  8. 1.6 7km SSE of Littlerock, CA
  9. 1.8 8km N of Glendora, CA
  10. 2.1 3km NE of Gardena, CA
  11. 1.6 2km NNW of Fontana, CA
  12. 1.5 2km E of Home Gardens, CA
  13. 1.5 4km SE of Home Gardens, CA
  14. 1.7 6km WNW of Fontana, CA
  15. 2.6 2km WSW of Silver Lake, 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 4.5 on 2020-09-19 — it released about 1,400 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.