QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

4km NE of Running Springs, CA

· 1.8 km deep · released about 40 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 89 kmSan Bernardino County 108 kmLos Angeles County 109 kmRiverside 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 2.1 (ml)
Depth
1.8 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Orange County, 89 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1979 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 3 people have reported feeling it to USGS.

How big was it?

This earthquake released about 40 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
  3. Around the size people start to feel M 3.0 24× the energy of this one
  4. This earthquake M 2.1 about 40 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 34.2275, -117.0763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 89 km (55 mi) NE of here earthquakes near Orange County
San Bernardino County, CA 108 km (67 mi) SW of here earthquakes near San Bernardino County
Los Angeles County, CA 109 km (68 mi) E of here earthquakes near Los Angeles County
Riverside County, CA 113 km (70 mi) WNW of here earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.6 10km N of Big Bear Lake, CA
  2. 1.5 3km ENE of Big Bear City, CA
  3. 2.0 5km ESE of Yucaipa, CA
  4. 2.6 3km ENE of San Jacinto, CA
  5. 1.8 5km S of Devore, CA
  6. 1.5 10km ENE of Cabazon, CA
  7. 1.9 7km ENE of Nuevo, CA
  8. 1.7 7km ENE of Nuevo, CA
  9. 1.8 4km SW of Redlands, CA
  10. 1.7 5km SSW of Redlands, CA
  11. 1.5 4km SE of Loma Linda, CA
  12. 2.2 3km WSW of Rubidoux, CA
  13. 1.9 2km SSW of Rancho Cucamonga, CA
  14. 2.1 3km W of Calimesa, CA
  15. 2.3 7km NNW of Big Bear 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 2018-05-08 — it released about 4,100 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.