Earthquake near Big Bear Lake, 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 33 km (21 mi) from the epicentre. In Big Bear Lake, 9 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 9 km, intensity III · Big Bear City 10 km, intensity III · Lucerne Valley 14 km, intensity III · Lake Arrowhead 26 km, intensity II · Apple Valley 31 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 780 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
2. Magna, Utah 2020 M 5.7 14,000× the energy of this one
3. Around the size people start to feel M 3.0 1.2× the energy of this one
4. This earthquake M 2.9 about 780 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 210 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

1. 7.3 The 1992 Landers, California Earthquake · 47 km ESE of this epicentre Jun 28, 1992
2. 6.3 The 1992 Big Bear, California Earthquake · 16 km SSE of this epicentre Jun 28, 1992
3. 6.2 3 km SE of San Bernardino, California · 41 km SW of this epicentre Jul 23, 1923
4. 6.0 The 1986 North Palm Springs, California Earthquake · 47 km SE of this epicentre Jul 8, 1986
5. 5.6 7km ENE of Running Springs, CA · 14 km SW 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 34.3262, -116.9235. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.9 4km SE of Yucaipa, CA 01:46 UTC
2. 1.6 6km SE of Loma Linda, CA 01:11 UTC
3. 2.7 3km WSW of Redlands, CA 07:03 UTC
4. 1.7 8km ESE of Big Bear City, CA 10:34 UTC
5. 1.8 26km N of Yucca Valley, CA 00:48 UTC
6. 1.5 4km NNW of Yucca Valley, CA 07:46 UTC
7. 3.0 4km NNW of Yucca Valley, CA 03:57 UTC
8. 3.1 2km N of Cabazon, CA 00:33 UTC
9. 1.6 7km NE of Banning, CA 20:05 UTC
10. 2.0 2km N of Muscoy, CA 05:48 UTC
11. 2.1 2km N of Muscoy, CA 05:48 UTC
12. 1.5 27km N of Yucca Valley, CA 01:08 UTC
13. 1.6 8km E of Cabazon, CA 23:52 UTC
14. 1.8 10km NNE of Running Springs, CA 22:08 UTC
15. 1.7 4km NNW of Yucca Valley, CA 21:33 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 23:41 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.