QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Running Springs, CA

No earthquake was likely felt in Running Springs in the 24 hours to 12:22 am PST (08:22 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 2.5 earthquake was recorded 10 km (6 mi) northeast of Running Springs, CA, at 5:25 am PDT on 14 September 2017 (12:25 UTC), 1.9 km deep. 2 people have reported feeling it to USGS.

USGS: 10km NE of Running Springs, CA

21 km (13 mi) NE of Highland, CA · 130 km (81 mi) ENE of Los Angeles, CA

5:25 am PDT, Sep 14, 2017 · · 1.9 km deep · released about 160 lb of TNT

10 km30 km60 km120 km N Orange County 95 kmSan Bernardino County 102 kmRiverside County 112 kmLos Angeles 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
5:25 am PDT on 14 September 2017 ()
Where
10 km (6 mi) northeast of Running Springs, CA · earthquakes near Running Springs
Magnitude
M 2.5 (ml)
Depth
1.9 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Orange County, 95 km SW
Nearest mapped fault
Cleghorn fault, 16 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 1558 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 22 km (14 mi) from the epicentre. In Running Springs, 10 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: Big Bear Lake 11 km, intensity II · Lake Arrowhead 15 km, intensity II · Big Bear City 17 km, intensity II · Lucerne Valley 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 160 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 95,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 68,000× the energy of this one
  3. Around the size people start to feel M 3.0 6× the energy of this one
  4. This earthquake M 2.5 about 160 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 4.4 on 2016-01-06 — about 730 times the energy of this one.

Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 The 1992 Big Bear, California Earthquake · 20 km ESE of this epicentre
  2. 6.2 3 km SE of San Bernardino, California · 29 km SW of this epicentre
  3. 6.0 The 1986 North Palm Springs, California Earthquake · 49 km SE of this epicentre
  4. 5.6 7km ENE of Running Springs, CA · 3 km SSW of this epicentre
  5. 5.5 11km SSE of Big Bear Lake, California · 20 km SE 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 34.2692, -117.0300. 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
Riverside County, CA 112 km (70 mi) ESE earthquakes near Riverside County
Los Angeles County, CA 114 km (71 mi) W earthquakes near Los Angeles County

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

Aftershocks so far

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

  1. 2.6 3km SE of Loma Linda, CA
  2. 1.6 3km ESE of Loma Linda, CA
  3. 2.7 5km E of Calimesa, CA
  4. 2.7 2km ESE of Loma Linda, CA
  5. 1.5 5km ENE of Rancho Cucamonga, CA
  6. 1.5 3km ESE of Loma Linda, CA
  7. 2.5 10km N of Lytle Creek, CA
  8. 2.3 1km NNW of Colton, CA
  9. 1.5 6km N of Big Bear City, CA
  10. 2.2 4km SE of Yucaipa, CA
  11. 1.7 14km SW of Lucerne Valley, CA
  12. 1.7 6km SSE of Beaumont, CA
  13. 1.7 2km SSE of Muscoy, CA
  14. 1.6 2km ESE of Loma Linda, CA
  15. 2.1 2km NNE 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.