QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Running Springs, CA

No earthquake was likely felt in Running Springs in the 24 hours to 4:35 am PST (12:35 UTC). The last one was M 2.0, 13 km (8 mi) WSW, at 3:40 pm PDT on 22 September 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Running Springs

This page: a magnitude 1.8 earthquake was recorded 11 km (7 mi) east-southeast of Running Springs, CA, at 3:28 pm PDT on 18 May 2018 (22:28 UTC), 7.8 km deep.

USGS: 11km ESE of Running Springs, CA

14 km (9 mi) NNE of Yucaipa, CA · 130 km (81 mi) E of Los Angeles, CA

3:28 pm PDT, May 18, 2018 · · 7.8 km deep · released about 16 lb of TNT

Every earthquake near Running Springs Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 89 kmRiverside County 104 kmSan Bernardino County 108 kmLos Angeles County 116 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
3:28 pm PDT on 18 May 2018 ()
Where
11 km (7 mi) east-southeast of Running Springs, CA · earthquakes near Running Springs
Magnitude
M 1.8 (ml)
Depth
7.8 km below the surface
Felt
no reports yet
Nearest
Orange County, 89 km SW
Nearest mapped fault
San Andreas fault, 6 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 3030 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 11 km (7 mi) from the epicentre. In Running Springs, 11 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: Big Bear Lake, Yucaipa, Mentone, Calimesa, Big Bear City, Highland.

How big was it?

This earthquake released about 16 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.

  1. Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 10,000 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1918 San Jacinto, California Earthquake · 44 km S of this epicentre
  2. 6.3 The 1992 Big Bear, California Earthquake · 17 km ENE of this epicentre
  3. 6.2 3 km SE of San Bernardino, California · 25 km WSW of this epicentre
  4. 6.0 The 1986 North Palm Springs, California Earthquake · 41 km ESE of this epicentre
  5. 5.6 7km ENE of Running Springs, CA · 10 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 34.1577, -117.0053. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 89 km (55 mi) SW earthquakes near Orange County
Riverside County, CA 104 km (65 mi) ESE earthquakes near Riverside County
San Bernardino County, CA 108 km (67 mi) NE earthquakes near San Bernardino County
Los Angeles County, CA 116 km (72 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

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

  1. 2.1 4km NW of Glen Avon, CA
  2. 1.5 9km NW of Garnet, CA
  3. 2.1 2km SSE of Devore, CA
  4. 1.7 3km SE of Loma Linda, CA
  5. 2.1 10km NNW of Big Bear Lake, CA
  6. 1.6 10km NNW of Big Bear Lake, CA
  7. 1.5 16km N of Cabazon, CA
  8. 1.5 8km ENE of Cabazon, CA
  9. 2.0 2km SE of Loma Linda, CA
  10. 1.5 12km NNE of Morongo Valley, CA
  11. 1.8 4km W of Banning, CA
  12. 2.3 12km N of Cabazon, CA
  13. 2.6 4km SE of Loma Linda, CA
  14. 1.7 7km NW of Banning, CA
  15. 1.9 10km N of Cabazon, 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.