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 18 km (11 mi) from the epicentre. In Running Springs, 6 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: Lake Arrowhead 9 km, intensity II · Big Bear Lake 17 km, intensity II · Highland 18 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 88 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 170,000× the energy of this one
2. Magna, Utah 2020 M 5.7 120,000× the energy of this one
3. Around the size people start to feel M 3.0 11× the energy of this one
4. This earthquake M 2.3 about 88 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 1,900 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 · 25 km ESE of this epicentre Jun 28, 1992
2. 6.2 3 km SE of San Bernardino, California · 24 km SW of this epicentre Jul 23, 1923
3. 5.6 7km ENE of Running Springs, CA · 6 km ESE of this epicentre Oct 16, 1999
4. 5.5 11km SSE of Big Bear Lake, California · 25 km ESE of this epicentre Jun 28, 1992
5. 5.3 Near San Bernardino, California · 7 km S 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 34.2598, -117.0948. Map © OpenStreetMap contributors.

Nearby places

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. 2.3 10 km NNE of Cabazon, CA 15:17 UTC
2. 2.2 7 km E of Yucaipa, CA 07:04 UTC
3. 2.7 6 km NW of Rialto, CA 05:49 UTC
4. 2.3 7 km NE of Moreno Valley, CA 12:47 UTC
5. 2.0 2 km E of Redlands, CA 18:04 UTC
6. 1.5 2 km NNE of Big Bear City, CA 21:15 UTC
7. 2.0 4 km SE of Loma Linda, CA 05:44 UTC
8. 1.6 8 km ENE of Running Springs, CA 13:57 UTC
9. 1.6 12 km SW of Morongo Valley, CA 12:37 UTC
10. 2.0 4 km E of Loma Linda, CA 09:12 UTC
11. 1.8 8 km ESE of Running Springs, CA 05:34 UTC
12. 3.1 7 km NNW of Banning, CA 23:37 UTC
13. 1.5 4 km SSE of Redlands, CA 15:50 UTC
14. 1.6 4 km SSE of Redlands, CA 10:54 UTC
15. 2.6 4 km SSE of Redlands, CA 09:24 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 20:50 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.