Earthquake near Running Springs, CA

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, 9 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.

Likely felt in: Mentone 10 km, intensity II · Yucaipa 11 km, intensity II · Highland 14 km, intensity II · Redlands 14 km, intensity II · Lake Arrowhead 17 km, intensity II · Big Bear Lake 19 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 150 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 5.8 100,000× the energy of this one
2. Magna, Utah 2020 M 5.7 72,000× the energy of this one
3. Around the size people start to feel M 3.0 6.5× the energy of this one
4. This earthquake M 2.5 about 150 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 1,100 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

1. 6.7 The 1918 San Jacinto, California Earthquake · 42 km SSE of this epicentre Apr 21, 1918
2. 6.3 The 1992 Big Bear, California Earthquake · 23 km ENE of this epicentre Jun 28, 1992
3. 6.2 3 km SE of San Bernardino, California · 19 km WSW of this epicentre Jul 23, 1923
4. 6.0 The 1986 North Palm Springs, California Earthquake · 44 km ESE of this epicentre Jul 8, 1986
5. 5.6 7km ENE of Running Springs, CA · 12 km N of this epicentre Oct 16, 1999

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 34.1327, -117.0620. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.3 2km E of Loma Linda, CA 02:23 UTC
2. 2.0 6km W of Calimesa, CA 21:43 UTC
3. 2.2 4km NE of Muscoy, CA 14:40 UTC
4. 2.5 3km ENE of Muscoy, CA 01:47 UTC
5. 1.5 5km SSW of Lytle Creek, CA 12:12 UTC
6. 2.1 7km N of Moreno Valley, CA 04:41 UTC
7. 1.6 6km NE of San Jacinto, CA 02:50 UTC
8. 1.6 10km N of Banning, CA 18:34 UTC
9. 1.5 4km SSW of Redlands, CA 03:31 UTC
10. 1.6 6km WSW of Fontana, CA 20:22 UTC
11. 1.5 5km NW of Morongo Valley, CA 12:37 UTC
12. 1.5 11km SSW of Morongo Valley, CA 19:37 UTC
13. 1.5 4km W of Lytle Creek, CA 13:32 UTC
14. 2.0 4km NNW of Green Acres, CA 09:07 UTC
15. 1.6 10km E of Yucaipa, CA 06:07 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 17:29 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.