QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Redlands, CA

No earthquake was likely felt in Redlands in the 24 hours to 6:49 am PST (14:49 UTC). The last one was M 2.0, 9 km (5 mi) SSE, at 10:33 pm PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Redlands

This page: a magnitude 1.9 earthquake was recorded 5 km (3 mi) south-southwest of Redlands, CA, at 5:07 pm PST on 10 January 2021 (01:07 UTC), 9.1 km deep.

USGS: 5km SSW of Redlands, CA

5 km (3 mi) SW of Redlands, CA · 111 km (69 mi) E of Los Angeles, CA

5:07 pm PST, Jan 10, 2021 · · 9.1 km deep · released about 19 lb of TNT

10 km30 km60 km120 km N Orange County 65 kmLos Angeles County 99 kmRiverside County 116 kmSan Diego County 118 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
5:07 pm PST on 10 January 2021 ()
Where
5 km (3 mi) south-southwest of Redlands, CA · earthquakes near Redlands
Magnitude
M 1.9 (ml)
Depth
9.1 km below the surface
Felt
no reports yet
Nearest
Orange County, 65 km SW
Nearest mapped fault
Crafton Hills fault, under 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 2131 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 11 km (7 mi) from the epicentre. In Redlands, 5 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: Redlands 5 km, intensity II · Loma Linda 6 km, intensity II · Mentone 9 km, intensity II · Moreno Valley 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 790,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 560,000× the energy of this one
  3. Around the size people start to feel M 3.0 50× the energy of this one
  4. This earthquake M 1.9 about 19 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 8,500 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. 6.7 The 1918 San Jacinto, California Earthquake · 36 km SE of this epicentre
  2. 6.3 The 1992 Big Bear, California Earthquake · 41 km ENE of this epicentre
  3. 6.2 3 km SE of San Bernardino, California · 9 km NNW of this epicentre
  4. 6.0 The 1910 Lake Elsinore, California Earthquake · 40 km SSW of this epicentre
  5. 5.6 7km ENE of Running Springs, CA · 29 km NNE 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 34.0192, -117.2073. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 65 km (40 mi) SW earthquakes near Orange County
Los Angeles County, CA 99 km (62 mi) WNW earthquakes near Los Angeles County
Riverside County, CA 116 km (72 mi) ESE earthquakes near Riverside County
San Diego County, CA 118 km (73 mi) SSE earthquakes near San Diego County
San Bernardino County, CA 132 km (82 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

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

  1. 1.5 9km N of Big Bear Lake, CA
  2. 1.7 9km N of Big Bear Lake, CA
  3. 1.5 10km NNE of Banning, CA
  4. 1.9 10km NNE of Running Springs, CA
  5. 1.8 17km SE of Big Bear City, CA
  6. 2.1 13km NNE of Cabazon, CA
  7. 3.2 9km NNW of Cabazon, CA
  8. 1.9 17km SE of Big Bear City, CA
  9. 1.7 1km ESE of Loma Linda, CA
  10. 1.6 3km WSW of Redlands, CA
  11. 1.6 17km SE of Big Bear City, CA
  12. 1.6 17km SE of Big Bear City, CA
  13. 1.6 3km S of Loma Linda, CA
  14. 1.7 6km S of Loma Linda, CA
  15. 1.7 16km SE of Big Bear City, 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.