Earthquake near Running Springs, CA

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 46 km (29 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: Lake Arrowhead 13 km, intensity III · Big Bear Lake 14 km, intensity III · Lucerne Valley 19 km, intensity III · Big Bear City 20 km, intensity III · Highland 22 km, intensity II · Mentone 25 km, intensity II · Apple Valley 27 km, intensity II · Hesperia 27 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 2,000 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 170,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 7,700× the energy of this one
3. Magna, Utah 2020 M 5.7 5,400× the energy of this one
4. This earthquake M 3.2 about 2,000 lb of TNT
5. Around the size people start to feel M 3.0 this one released 2.1× more

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 59 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 · 23 km ESE of this epicentre Jun 28, 1992
2. 6.2 3 km SE of San Bernardino, California · 29 km SW of this epicentre Jul 23, 1923
3. 5.6 7km ENE of Running Springs, CA · 5 km SSE of this epicentre Oct 16, 1999
4. 5.5 11km SSE of Big Bear Lake, California · 23 km SE of this epicentre Jun 28, 1992
5. 5.3 Near San Bernardino, California · 10 km SSW of this epicentre Sep 20, 1907

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 34.2860, -117.0582. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.5 4km N of Banning, CA 02:07 UTC
2. 2.0 1km NNE of Calimesa, CA 11:26 UTC
3. 1.7 6km ENE of Lake Arrowhead, CA 18:49 UTC
4. 1.8 4km E of Running Springs, CA 10:01 UTC
5. 2.3 5km S of Lytle Creek, CA 14:59 UTC
6. 2.5 7km E of Calimesa, CA 07:51 UTC
7. 2.0 7km E of Calimesa, CA 04:49 UTC
8. 1.6 7km E of Calimesa, CA 03:34 UTC
9. 2.2 2km N of Colton, CA 00:38 UTC
10. 1.5 7km E of Calimesa, CA 17:18 UTC
11. 1.7 15km N of Cabazon, CA 03:46 UTC
12. 1.6 15km NNE of Apple Valley, CA 23:09 UTC
13. 1.6 7km NW of Banning, CA 02:46 UTC
14. 1.6 7km NE of Beaumont, CA 05:24 UTC
15. 3.0 7km NE of Beaumont, CA 04:39 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 06:24 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

• The official USGS event page — the source of record for every value above
• Did you feel it? Report it to USGS — reports go to USGS, not to us
• ShakeMap for this event, when USGS has produced one

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