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 11:24 am PST (19:24 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 17 km (10 mi) south of Big Bear City, CA, at 12:02 am PDT on 19 August 2021 (07:02 UTC), 6.3 km deep.

USGS: 17km S of Big Bear City, CA

22 km (14 mi) ENE of Yucaipa, CA · 146 km (91 mi) E of Los Angeles, CA

12:02 am PDT, Aug 19, 2021 · · 6.3 km deep · released about 17 lb of TNT

Every earthquake near Big Bear City Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Riverside County 87 kmOrange County 100 kmSan Bernardino County 102 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
12:02 am PDT on 19 August 2021 ()
Where
17 km (10 mi) south of Big Bear City, CA · earthquakes near Big Bear City
Magnitude
M 1.8 (ml)
Depth
6.3 km below the surface
Felt
no reports yet
Nearest
Riverside County, 87 km ESE
Nearest mapped fault
San Andreas fault, 4 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 1911 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 12 km (7 mi) from the epicentre. In Big Bear City, 17 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.

Earthquakes near other towns within 30 km: Big Bear Lake, Cherry Valley, Banning, Yucaipa, Cabazon, Morongo Valley.

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 37 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.3 The 1992 Landers, California Earthquake · 37 km ENE of this epicentre
  2. 6.7 The 1918 San Jacinto, California Earthquake · 41 km SSW of this epicentre
  3. 6.3 The 1992 Big Bear, California Earthquake · 10 km N of this epicentre
  4. 6.2 3 km SE of San Bernardino, California · 40 km W of this epicentre
  5. 6.1 The 1992 Joshua Tree, California Earthquake · 50 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 34.1122, -116.8250. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Riverside County, CA 87 km (54 mi) ESE earthquakes near Riverside County
Orange County, CA 100 km (62 mi) WSW earthquakes near Orange County
San Bernardino County, CA 102 km (63 mi) NE earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 2.0 3km SE of Loma Linda, CA
  2. 1.7 6km NE of Cabazon, CA
  3. 1.8 13km SE of Big Bear City, CA
  4. 1.5 2km E of Yucaipa, CA
  5. 2.5 6km E of Yucaipa, CA
  6. 2.2 13km SE of Big Bear City, CA
  7. 1.7 13km SE of Big Bear City, CA
  8. 1.5 13km SE of Big Bear City, CA
  9. 1.5 13km SE of Big Bear City, CA
  10. 2.1 3km SW of San Bernardino, CA
  11. 1.6 3km E of Loma Linda, CA
  12. 1.7 3km WSW of Yucaipa, CA
  13. 1.6 7km NW of Big Bear City, CA
  14. 2.2 5km N of Moreno Valley, CA
  15. 2.4 7km S of Redlands, 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.