QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Calimesa, CA

No earthquake was likely felt in Calimesa in the 24 hours to 2:48 am PST (10:48 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 2.5 earthquake was recorded 8 km (5 mi) east of Calimesa, CA, at 12:51 am PDT on 29 September 2017 (07:51 UTC), 4.9 km deep. 7 people have reported feeling it to USGS.

USGS: 7km E of Calimesa, CA

7 km (5 mi) SE of Yucaipa, CA · 132 km (82 mi) E of Los Angeles, CA

12:51 am PDT, Sep 29, 2017 · · 4.9 km deep · released about 150 lb of TNT

10 km30 km60 km120 km N Orange County 82 kmRiverside County 95 kmSan Diego County 110 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
12:51 am PDT on 29 September 2017 ()
Where
8 km (5 mi) east of Calimesa, CA · earthquakes near Calimesa
Magnitude
M 2.5 (ml)
Depth
4.9 km below the surface
Felt
7 reports · strongest reported intensity III
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

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 21 km (13 mi) from the epicentre. In Calimesa, 8 km away, the estimate is intensity III (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 III · Yucaipa 7 km, intensity III · Banning 12 km, intensity II · Mentone 17 km, intensity II · Redlands 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 150 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 72,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.5× the energy of this one
  4. This earthquake M 2.5 about 150 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 790 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1918 San Jacinto, California Earthquake · 26 km S of this epicentre
  2. 6.3 The 1992 Big Bear, California Earthquake · 27 km NNE of this epicentre
  3. 6.2 3 km SE of San Bernardino, California · 28 km WNW of this epicentre
  4. 6.0 The 1986 North Palm Springs, California Earthquake · 34 km E of this epicentre
  5. 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 33.9942, -116.9788. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection 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
Los Angeles County, CA 120 km (75 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 121 km (75 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

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

  1. 1.6 3km ESE of Loma Linda, CA
  2. 2.7 5km E of Calimesa, CA
  3. 2.7 2km ESE of Loma Linda, CA
  4. 1.7 5km S of Idyllwild, CA
  5. 1.9 8km SE of Valle Vista, CA
  6. 1.5 3km ESE of Loma Linda, CA
  7. 2.3 1km NNW of Colton, CA
  8. 1.5 6km N of Big Bear City, CA
  9. 1.5 2km W of San Jacinto, CA
  10. 2.2 4km SE of Yucaipa, CA
  11. 1.9 7km SSW of Idyllwild, CA
  12. 1.7 14km SW of Lucerne Valley, CA
  13. 1.8 16km SSE of Hemet, CA
  14. 1.7 6km SSE of Beaumont, CA
  15. 1.7 2km SSE of Muscoy, 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.