Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Redlands, CA
No earthquake was likely felt in Redlands in the 24 hours to 2:34 am PST (10:34 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 1.8 earthquake was recorded in Redlands, CA, at 1:21 am PST on 20 November 2017 (09:21 UTC), 12 km deep.
USGS: 2km NE of Redlands, CA
in Redlands, CA · 114 km (71 mi) E of Los Angeles, CA
- When
- 1:21 am PST on 20 November 2017 ()
- Where
- in Redlands, CA · earthquakes near Redlands
- Magnitude
- M 1.8 (ml)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Orange County, 71 km SW
- Nearest mapped fault
- Crafton Hills fault, 2 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 3279 days ago
Earthquake alerts for Redlands, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 7 km (4 mi) from the epicentre. 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 in town, intensity II · Mentone 3 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.
- Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
- Magna, Utah 2020 M 5.7 620,000× the energy of this one
- Around the size people start to feel M 3.0 55× the energy of this one
- 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 4.4 on 2016-01-06 — about 6,700 times the energy of this one.
Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 The 1918 San Jacinto, California Earthquake · 39 km SSE of this epicentre
- 6.3 The 1992 Big Bear, California Earthquake · 35 km ENE of this epicentre
- 6.2 3 km SE of San Bernardino, California · 9 km WNW of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 46 km SSW of this epicentre
- 5.6 7km ENE of Running Springs, CA · 23 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 34.0670, -117.1703. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 71 km (44 mi) | SW | earthquakes near Orange County |
| Los Angeles County, CA | 101 km (63 mi) | W | earthquakes near Los Angeles County |
| Riverside County, CA | 114 km (71 mi) | ESE | earthquakes near Riverside County |
| San Diego County, CA | 122 km (76 mi) | SSE | earthquakes near San Diego County |
| San Bernardino County, CA | 126 km (78 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
49 earthquakes have been recorded within 50 km since this one.
- 1.5 12km NNE of Cabazon, CA
- 2.0 4km SW of Redlands, CA
- 1.9 11km NNE of Trabuco Canyon, CA
- 1.6 3km N of Rancho Cucamonga, CA
- 2.5 11km NNE of Trabuco Canyon, CA
- 1.5 3km ENE of Rialto, CA
- 3.1 4km SE of Ontario, CA
- 2.6 11km NNE of Trabuco Canyon, CA
- 2.1 11km NNE of Trabuco Canyon, CA
- 1.5 6km N of Big Bear City, CA
- 3.2 6km N of Big Bear City, CA
- 1.6 4km WNW of Muscoy, CA
- 1.7 4km S of Redlands, CA
- 1.6 2km W of Devore, CA
- 2.2 9km SW of Lytle Creek, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.