QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Big Bear Lake, CA

No earthquake was likely felt in Big Bear Lake in the 24 hours to 10:20 am PST (18:20 UTC). The last one was M 2.6, 7 km (4 mi) NE, at 1:40 am PDT on 6 October 2026, estimated intensity III (weak) in town; 18 felt reports to USGS. Every earthquake near Big Bear Lake

This page: a magnitude 1.8 earthquake was recorded 12 km (7 mi) south-southwest of Big Bear Lake, CA, at 9:48 am PST on 8 December 2023 (17:48 UTC), 1.1 km deep. 2 people have reported feeling it to USGS.

USGS: 12 km SSW of Big Bear Lake, CA

15 km (9 mi) NNE of Yucaipa, CA · 134 km (83 mi) E of Los Angeles, CA

9:48 am PST, Dec 8, 2023 · · 1.1 km deep · released about 17 lb of TNT

Every earthquake near Big Bear Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 91 kmRiverside County 100 kmSan Bernardino County 107 kmLos Angeles County 119 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
9:48 am PST on 8 December 2023 ()
Where
12 km (7 mi) south-southwest of Big Bear Lake, CA · earthquakes near Big Bear Lake
Magnitude
M 1.8 (ml)
Depth
1.1 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Orange County, 91 km SW
Nearest mapped fault
San Andreas fault, 5 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 1070 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 14 km (9 mi) from the epicentre. In Big Bear Lake, 12 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: Big Bear Lake 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 9,800 times the energy of this one.

Before 2016, the USGS record lists 24 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.3 The 1992 Landers, California Earthquake · 49 km E of this epicentre
  2. 6.7 The 1918 San Jacinto, California Earthquake · 43 km S of this epicentre
  3. 6.3 The 1992 Big Bear, California Earthquake · 14 km ENE of this epicentre
  4. 6.2 3 km SE of San Bernardino, California · 28 km WSW of this epicentre
  5. 6.0 The 1986 North Palm Springs, California Earthquake · 37 km ESE 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 34.1477, -116.9660. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 91 km (57 mi) SW earthquakes near Orange County
Riverside County, CA 100 km (62 mi) ESE earthquakes near Riverside County
San Bernardino County, CA 107 km (66 mi) NE earthquakes near San Bernardino County
Los Angeles County, CA 119 km (74 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

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

  1. 1.5 6 km NNE of Beaumont, CA
  2. 1.6 2 km E of Loma Linda, CA
  3. 1.6 19 km WNW of Morongo Valley, CA
  4. 1.8 6 km SSE of Redlands, CA
  5. 1.6 8 km ENE of Yucaipa, CA
  6. 1.9 6 km NNE of Big Bear Lake, CA
  7. 1.7 6 km NNE of Big Bear Lake, CA
  8. 1.5 3 km N of Colton, CA
  9. 1.5 5 km E of Cabazon, CA
  10. 2.6 6 km NW of Big Bear City, CA
  11. 2.0 6 km NW of Big Bear City, CA
  12. 2.8 6 km WNW of Calimesa, CA
  13. 1.6 8 km SSE of Big Bear Lake, CA
  14. 1.6 4 km SSW of Beaumont, CA
  15. 1.5 5 km NE of Cabazon, 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.