Earthquake · reviewed by a seismologist
M 2.1ml
Earthquake near Loma Linda, CA
No earthquake was likely felt in Loma Linda in the 24 hours to 7:11 pm PST (03:11 UTC). The last one was M 2.1, 2 km (1 mi) SE, at 10:40 am PDT on 31 October 2026, estimated intensity II (weak) in town. Every earthquake near Loma Linda
This page: a magnitude 2.1 earthquake was recorded 4 km (2 mi) southeast of Loma Linda, CA, at 4:48 am PDT on 11 May 2021 (11:48 UTC), 17 km deep. 2 people have reported feeling it to USGS.
USGS: 4km SE of Loma Linda, CA
6 km (4 mi) WSW of Redlands, CA · 109 km (68 mi) E of Los Angeles, CA
- When
- 4:48 am PDT on 11 May 2021 ()
- Where
- 4 km (2 mi) southeast of Loma Linda, CA · earthquakes near Loma Linda
- Magnitude
- M 2.1 (ml)
- Depth
- 17 km below the surface
- Felt
- 2 reports · strongest reported intensity II
- Nearest
- Orange County, 64 km SW
- Nearest mapped fault
- San Jacinto 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 2011 days ago
Earthquake alerts for Loma Linda, 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 3 km (2 mi) from the epicentre. In Loma Linda, 4 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: Redlands, Grand Terrace, Colton, Highgrove, Moreno Valley, Mentone.
How big was it?
This earthquake released about 38 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.
- Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
- Magna, Utah 2020 M 5.7 280,000× the energy of this one
- Around the size people start to feel M 3.0 25× the energy of this one
- This earthquake M 2.1 about 38 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 4,300 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 · 38 km SE of this epicentre
- 6.3 The 1992 Big Bear, California Earthquake · 42 km ENE of this epicentre
- 6.2 3 km SE of San Bernardino, California · 8 km NNW of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 40 km SSW of this epicentre
- 5.6 7km ENE of Running Springs, CA · 30 km NE 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 34.0258, -117.2292. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 64 km (40 mi) | SW | earthquakes near Orange County |
| Los Angeles County, CA | 97 km (60 mi) | WNW | earthquakes near Los Angeles County |
| Riverside County, CA | 118 km (73 mi) | ESE | earthquakes near Riverside County |
| San Diego County, CA | 119 km (74 mi) | SSE | earthquakes near San Diego County |
| San Bernardino County, CA | 133 km (83 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
51 earthquakes have been recorded within 50 km since this one.
- 2.2 4km NW of Muscoy, CA
- 1.5 3km NE of Grand Terrace, CA
- 1.6 4km ENE of Big Bear City, CA
- 1.5 4km SSW of Redlands, CA
- 1.7 6km NNE of Big Bear City, CA
- 1.6 10km N of Big Bear Lake, CA
- 1.5 3km ENE of Big Bear City, CA
- 1.8 8km SSE of Home Gardens, CA
- 2.0 5km ESE of Yucaipa, CA
- 2.6 3km ENE of San Jacinto, CA
- 1.8 5km S of Devore, CA
- 1.6 2km N of Claremont, CA
- 1.9 7km ENE of Nuevo, CA
- 1.7 7km ENE of Nuevo, CA
- 1.8 11km W of Corona, 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.