QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Running Springs, CA

No earthquake was likely felt in Running Springs in the 24 hours to 10:27 am PST (18:27 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 1.5 earthquake was recorded 10 km (6 mi) northeast of Running Springs, CA, at 1:23 am PST on 10 December 2023 (09:23 UTC), 5.9 km deep.

USGS: 10 km NE of Running Springs, CA

22 km (14 mi) NNE of Highland, CA · 129 km (80 mi) ENE of Los Angeles, CA

1:23 am PST, Dec 10, 2023 · · 5.9 km deep · released about 6.2 lb of TNT

10 km30 km60 km120 km N Orange County 95 kmSan Bernardino County 102 kmLos Angeles County 112 kmRiverside 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
1:23 am PST on 10 December 2023 ()
Where
10 km (6 mi) northeast of Running Springs, CA · earthquakes near Running Springs
Magnitude
M 1.5 (ml)
Depth
5.9 km below the surface
Felt
no reports yet
Nearest
Orange County, 95 km SW
Nearest mapped fault
Cleghorn fault, 15 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 1066 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 9 km (6 mi) from the epicentre. In Running Springs, 10 km away, the estimate is intensity II (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.

Earthquakes near other towns within 30 km: Big Bear Lake, Lake Arrowhead, Big Bear City, Lucerne Valley, Crestline, Highland.

How big was it?

This earthquake released about 6.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 27,000 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 The 1992 Big Bear, California Earthquake · 22 km ESE of this epicentre
  2. 6.2 3 km SE of San Bernardino, California · 29 km SW of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 5 km S of this epicentre
  4. 5.5 11km SSE of Big Bear Lake, California · 22 km SE of this epicentre
  5. 5.4 26km NNW of Yucca Valley, CA · 49 km E 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 34.2832, -117.0452. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 95 km (59 mi) SW earthquakes near Orange County
San Bernardino County, CA 102 km (63 mi) NE earthquakes near San Bernardino County
Los Angeles County, CA 112 km (70 mi) W earthquakes near Los Angeles County
Riverside County, CA 114 km (71 mi) ESE earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.5 6 km E of Calimesa, CA
  2. 1.6 6 km NNE of Beaumont, CA
  3. 1.7 1 km N of Beaumont, CA
  4. 1.6 4 km NE of Beaumont, CA
  5. 1.9 12 km N of Cabazon, CA
  6. 1.5 6 km NNE of Beaumont, CA
  7. 1.6 2 km E of Loma Linda, CA
  8. 1.6 19 km WNW of Morongo Valley, CA
  9. 1.5 8 km SE of Wrightwood, CA
  10. 1.8 6 km SSE of Redlands, CA
  11. 1.6 8 km ENE of Yucaipa, CA
  12. 1.9 6 km NNE of Big Bear Lake, CA
  13. 1.7 6 km NNE of Big Bear Lake, CA
  14. 1.5 3 km N of Colton, CA
  15. 1.5 5 km E of Cabazon, 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.