Earthquake · reviewed by a seismologist
M 1.6ml
Earthquake near Calimesa, CA
No earthquake was likely felt in Calimesa in the 24 hours to 2:33 am PST (10:33 UTC). The last one was M 2.0, 7 km (4 mi) WSW, at 10:33 pm PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Calimesa
This page: a magnitude 1.6 earthquake was recorded 8 km (5 mi) east of Calimesa, CA, at 8:34 pm PDT on 28 September 2017 (03:34 UTC), 3.5 km deep.
USGS: 7km E of Calimesa, CA
7 km (5 mi) SE of Yucaipa, CA · 132 km (82 mi) E of Los Angeles, CA
- When
- 8:34 pm PDT on 28 September 2017 ()
- Where
- 8 km (5 mi) east of Calimesa, CA · earthquakes near Calimesa
- Magnitude
- M 1.6 (ml)
- Depth
- 3.5 km below the surface
- Felt
- no reports yet
- Nearest
- Orange County, 82 km WSW
- Nearest mapped fault
- San Gorgonio Pass 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 3303 days ago
Earthquake alerts for Calimesa, 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 11 km (7 mi) from the epicentre. In Calimesa, 8 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: Beaumont 7 km, intensity II · Yucaipa 7 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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 15,000 times the energy of this one.
Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 The 1918 San Jacinto, California Earthquake · 26 km S of this epicentre
- 6.3 The 1992 Big Bear, California Earthquake · 27 km NNE of this epicentre
- 6.2 3 km SE of San Bernardino, California · 28 km WNW of this epicentre
- 6.0 The 1986 North Palm Springs, California Earthquake · 34 km E of this epicentre
- 5.6 7km ENE of Running Springs, CA · 28 km NNW 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 33.9958, -116.9760. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 82 km (51 mi) | WSW | earthquakes near Orange County |
| Riverside County, CA | 95 km (59 mi) | ESE | earthquakes near Riverside County |
| San Diego County, CA | 110 km (68 mi) | S | earthquakes near San Diego County |
| San Bernardino County, CA | 120 km (75 mi) | NE | earthquakes near San Bernardino County |
| Los Angeles County, CA | 120 km (75 mi) | W | earthquakes near Los Angeles County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
45 earthquakes have been recorded within 50 km since this one.
- 2.7 5km E of Calimesa, CA
- 2.7 2km ESE of Loma Linda, CA
- 1.7 5km S of Idyllwild, CA
- 1.9 8km SE of Valle Vista, CA
- 1.5 3km ESE of Loma Linda, CA
- 2.3 1km NNW of Colton, CA
- 1.5 6km N of Big Bear City, CA
- 1.5 2km W of San Jacinto, CA
- 2.2 4km SE of Yucaipa, CA
- 1.9 7km SSW of Idyllwild, CA
- 1.7 14km SW of Lucerne Valley, CA
- 1.8 16km SSE of Hemet, CA
- 1.7 6km SSE of Beaumont, CA
- 1.7 2km SSE of Muscoy, CA
- 1.6 2km ESE of Loma Linda, 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.