QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Big Bear City, CA

No earthquake was likely felt in Big Bear City in the 24 hours to 4:52 am PST (12:52 UTC). The last one was M 1.5, 10 km (6 mi) ESE, at 12:11 pm PST on 3 November 2026, estimated intensity II (weak) in town. Every earthquake near Big Bear City

This page: a magnitude 1.8 earthquake was recorded 48 km (30 mi) north-northeast of Big Bear City, CA, at 7:54 pm PDT on 28 October 2023 (02:54 UTC), 8.8 km deep.

USGS: 39 km WSW of Ludlow, CA

60 km (37 mi) E of Apple Valley, CA · 108 km (67 mi) NE of Riverside, CA

7:54 pm PDT, Oct 28, 2023 · · 8.8 km deep · released about 13 lb of TNT

Every earthquake near Big Bear City Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Bernardino County 44 kmRiverside County 113 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
7:54 pm PDT on 28 October 2023 ()
Where
48 km (30 mi) north-northeast of Big Bear City, CA · earthquakes near Big Bear City
Magnitude
M 1.8 (ml)
Depth
8.8 km below the surface
Felt
no reports yet
Nearest
San Bernardino County, 44 km NE
Nearest mapped fault
Camp Rock-Emerson-Copper Mountain fault, 6 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 1110 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 10 km (6 mi) from the epicentre. In Big Bear City, 48 km away, the estimate is intensity I (not felt). 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.

How big was it?

This earthquake released about 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 4.3 on 2016-02-20 — about 6,700 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.3 The 1992 Landers, California Earthquake · 49 km SSE of this epicentre
  2. 7.1 The 1999 Hector Mine, California Earthquake · 28 km E of this epicentre
  3. 6.5 The 1947 Manix, California Earthquake · 40 km N of this epicentre
  4. 5.8 13km WSW of Ludlow, CA · 26 km ENE of this epicentre
  5. 5.4 26km NNW of Yucca Valley, CA · 32 km S 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 34.6285, -116.5687. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Bernardino County, CA 44 km (27 mi) NE earthquakes near San Bernardino County
Riverside County, CA 113 km (70 mi) SSE earthquakes near Riverside County
Orange County, CA 154 km (95 mi) SW earthquakes near Orange County

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

Aftershocks so far

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

  1. 1.7 13 km WSW of Ludlow, CA
  2. 1.9 13 km NW of Ludlow, CA
  3. 1.7 29 km N of Yucca Valley, CA
  4. 1.6 32 km N of Yucca Valley, CA
  5. 1.6 10 km NNW of Big Bear Lake, CA
  6. 1.8 20 km NE of Big Bear City, CA
  7. 2.6 14 km WSW of Ludlow, CA
  8. 1.7 19 km SW of Ludlow, CA
  9. 1.6 39 km NE of Big Bear City, CA
  10. 2.1 8 km N of Big Bear Lake, CA
  11. 1.7 37 km N of Yucca Valley, CA
  12. 1.7 22 km WNW of Ludlow, CA
  13. 2.1 15 km WSW of Ludlow, CA
  14. 1.9 19 km SW of Ludlow, CA
  15. 1.8 36 km SSE of Fort Irwin, 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.