QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Big Bear Lake, CA

No earthquake was likely felt in Big Bear Lake in the 24 hours to 4:59 am PST (12:59 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 2.1 earthquake was recorded 18 km (11 mi) south-southeast of Big Bear Lake, CA, at 10:03 pm PDT on 21 October 2020 (05:03 UTC), 2.2 km deep. 1 person has reported feeling it to USGS.

USGS: 18km SSE of Big Bear Lake, CA

18 km (11 mi) ENE of Yucaipa, CA · 144 km (89 mi) E of Los Angeles, CA

10:03 pm PDT, Oct 21, 2020 · · 2.2 km deep · released about 43 lb of TNT

Every earthquake near Big Bear Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Riverside County 88 kmOrange County 97 kmSan Bernardino County 105 kmSan Diego 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
10:03 pm PDT on 21 October 2020 ()
Where
18 km (11 mi) south-southeast of Big Bear Lake, CA · earthquakes near Big Bear Lake
Magnitude
M 2.1 (ml)
Depth
2.2 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Riverside County, 88 km ESE
Nearest mapped fault
San Andreas fault, 1 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 2212 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 17 km (11 mi) from the epicentre. In Big Bear Lake, 18 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: Cherry Valley, Banning, Yucaipa, Big Bear City, Cabazon, Beaumont.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 3,800 times the energy of this one.

Before 2016, the USGS record lists 35 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.3 The 1992 Landers, California Earthquake · 40 km ENE of this epicentre
  2. 6.7 The 1918 San Jacinto, California Earthquake · 38 km SSW of this epicentre
  3. 6.3 The 1992 Big Bear, California Earthquake · 13 km N of this epicentre
  4. 6.2 3 km SE of San Bernardino, California · 37 km W of this epicentre
  5. 6.0 The 1948 Desert Hot Springs, 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 34.0883, -116.8535. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Riverside County, CA 88 km (55 mi) ESE earthquakes near Riverside County
Orange County, CA 97 km (60 mi) WSW earthquakes near Orange County
San Bernardino County, CA 105 km (65 mi) NE earthquakes near San Bernardino County
San Diego County, CA 119 km (74 mi) S earthquakes near San Diego County

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

Aftershocks so far

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

  1. 1.8 5km SSW of Banning, CA
  2. 1.9 2km E of Moreno Valley, CA
  3. 1.6 2km SE of Muscoy, CA
  4. 1.5 4km WSW of Calimesa, CA
  5. 1.8 6km S of Mentone, CA
  6. 1.8 4km NNW of San Jacinto, CA
  7. 1.6 18km N of Yucca Valley, CA
  8. 1.8 10km SW of Morongo Valley, CA
  9. 1.6 4km SE of Loma Linda, CA
  10. 2.3 4km SE of Loma Linda, CA
  11. 2.1 4km SE of Loma Linda, CA
  12. 1.5 2km E of Loma Linda, CA
  13. 2.3 6km S of Beaumont, CA
  14. 1.5 6km SSW of Redlands, CA
  15. 2.2 8km SE of Valle Vista, 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.