QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Mentone, CA

No earthquake was likely felt in Mentone in the 24 hours to 6:39 am PST (14:39 UTC). The last one was M 2.0, 9 km (6 mi) S, at 10:33 pm PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Mentone

This page: a magnitude 1.5 earthquake was recorded 3 km (2 mi) southeast of Mentone, CA, at 1:34 pm PST on 26 February 2018 (21:34 UTC), 11 km deep.

USGS: 3km SE of Mentone, CA

5 km (3 mi) E of Redlands, CA · 120 km (74 mi) E of Los Angeles, CA

1:34 pm PST, Feb 26, 2018 · · 11 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N Orange County 74 kmLos Angeles County 107 kmRiverside County 109 kmSan Diego County 119 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
1:34 pm PST on 26 February 2018 ()
Where
3 km (2 mi) southeast of Mentone, CA · earthquakes near Mentone
Magnitude
M 1.5 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Orange County, 74 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 3179 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Mentone, 3 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, Yucaipa, Calimesa, Highland, Loma Linda, Cherry Valley.

How big was it?

This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 22,000 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1918 San Jacinto, California Earthquake · 35 km SSE of this epicentre
  2. 6.3 The 1992 Big Bear, California Earthquake · 31 km ENE of this epicentre
  3. 6.2 3 km SE of San Bernardino, California · 14 km WNW of this epicentre
  4. 6.0 The 1910 Lake Elsinore, California Earthquake · 47 km SW of this epicentre
  5. 6.0 The 1986 North Palm Springs, California Earthquake · 47 km E 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 34.0523, -117.1127. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 74 km (46 mi) SW earthquakes near Orange County
Los Angeles County, CA 107 km (66 mi) W earthquakes near Los Angeles County
Riverside County, CA 109 km (67 mi) ESE earthquakes near Riverside County
San Diego County, CA 119 km (74 mi) SSE earthquakes near San Diego County
San Bernardino County, CA 124 km (77 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. 1.6 7km NNE of Cabazon, CA
  2. 1.6 12km NE of Trabuco Canyon, CA
  3. 1.8 5km NNW of Big Bear City, CA
  4. 1.6 8km N of Fontana, CA
  5. 2.5 2km NE of Redlands, CA
  6. 1.9 2km NE of Redlands, CA
  7. 1.6 2km NE of Redlands, CA
  8. 1.5 10km N of Cabazon, CA
  9. 2.5 3km ENE of Upland, CA
  10. 1.7 7km N of Big Bear City, CA
  11. 1.5 9km NE of Big Bear City, CA
  12. 2.3 5km SSE of Mentone, CA
  13. 1.9 11km SSE of Lucerne Valley, CA
  14. 2.6 1km SSW of Loma Linda, CA
  15. 1.8 3km SE of San Jacinto, 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.