QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

Earthquake near Running Springs, CA

No earthquake was likely felt in Running Springs in the 24 hours to 4:32 am PST (12:32 UTC). The last one was M 2.0, 13 km (8 mi) WSW, at 3:40 pm PDT on 22 September 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Running Springs

This page: a magnitude 2.4 earthquake was recorded 5 km (3 mi) north-northeast of Running Springs, CA, at 12:11 pm PDT on 12 July 2021 (19:11 UTC), 4.6 km deep.

USGS: 5km NNE of Running Springs, CA

16 km (10 mi) NNE of Highland, CA · 123 km (77 mi) ENE of Los Angeles, CA

12:11 pm PDT, Jul 12, 2021 · · 4.6 km deep · released about 100 lb of TNT

Every earthquake near Running Springs Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 89 kmLos Angeles County 107 kmSan Bernardino County 108 kmRiverside County 116 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
12:11 pm PDT on 12 July 2021 ()
Where
5 km (3 mi) north-northeast of Running Springs, CA · earthquakes near Running Springs
Magnitude
M 2.4 (ml)
Depth
4.6 km below the surface
Felt
no reports yet
Nearest
Orange County, 89 km SW
Nearest mapped fault
Cleghorn fault, 11 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1948 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 20 km (12 mi) from the epicentre. In Running Springs, 5 km away, the estimate is intensity III (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Lake Arrowhead 8 km, intensity II · Highland 17 km, intensity II · Big Bear Lake 17 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 140,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 100,000× the energy of this one
  3. Around the size people start to feel M 3.0 9.1× the energy of this one
  4. This earthquake M 2.4 about 100 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.5 on 2018-05-08 — about 1,600 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 The 1992 Big Bear, California Earthquake · 26 km ESE of this epicentre
  2. 6.2 3 km SE of San Bernardino, California · 23 km SW of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 6 km E of this epicentre
  4. 5.5 11km SSE of Big Bear Lake, California · 25 km ESE of this epicentre
  5. 5.3 Near San Bernardino, California · 5 km S of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 34.2493, -117.0988. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 89 km (56 mi) SW earthquakes near Orange County
Los Angeles County, CA 107 km (67 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 108 km (67 mi) NE earthquakes near San Bernardino County
Riverside County, CA 116 km (72 mi) ESE earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.6 4km S of Lucerne Valley, CA
  2. 1.6 7km ENE of Cabazon, CA
  3. 1.6 5km NNE of Fontana, CA
  4. 2.6 5km NNE of Fontana, CA
  5. 2.6 5km SE of Loma Linda, CA
  6. 1.8 4km NE of Beaumont, CA
  7. 1.7 4km SE of Yucaipa, CA
  8. 1.6 4km SW of Highland, CA
  9. 1.9 7km NW of Big Bear City, CA
  10. 1.6 7km NW of Big Bear City, CA
  11. 1.6 8km SW of Beaumont, CA
  12. 1.9 14km NE of Big Bear City, CA
  13. 1.7 5km NNW of Beaumont, CA
  14. 2.0 3km E of Loma Linda, CA
  15. 1.7 2km ESE 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.