QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Yucaipa, CA

No earthquake was likely felt in Yucaipa in the 24 hours to 12:08 pm PST (20:08 UTC). The last one was M 1.5, 8 km (5 mi) ESE, at 3:54 pm PST on 9 November 2026, estimated intensity II (weak) in town. Every earthquake near Yucaipa

This page: a magnitude 1.8 earthquake was recorded 5 km (3 mi) east of Yucaipa, CA, at 10:40 am PDT on 12 May 2021 (17:40 UTC), 12 km deep.

USGS: 5km E of Yucaipa, CA

5 km (3 mi) E of Yucaipa, CA · 131 km (81 mi) E of Los Angeles, CA

10:40 am PDT, May 12, 2021 · · 12 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Orange County 83 kmRiverside County 97 kmSan Diego County 115 kmSan Bernardino County 117 kmLos Angeles 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
10:40 am PDT on 12 May 2021 ()
Where
5 km (3 mi) east of Yucaipa, CA · earthquakes near Yucaipa
Magnitude
M 1.8 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Orange County, 83 km WSW
Nearest mapped fault
San Andreas fault, 2 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 2010 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 7 km (4 mi) from the epicentre. In Yucaipa, 5 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: Yucaipa 5 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 11,000 times the energy of this one.

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

  1. 6.7 The 1918 San Jacinto, California Earthquake · 31 km S of this epicentre
  2. 6.3 The 1992 Big Bear, California Earthquake · 23 km NE of this epicentre
  3. 6.2 3 km SE of San Bernardino, California · 26 km WNW of this epicentre
  4. 6.0 The 1986 North Palm Springs, California Earthquake · 35 km E of this epicentre
  5. 5.6 7km ENE of Running Springs, CA · 23 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 34.0412, -116.9882. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 83 km (52 mi) WSW earthquakes near Orange County
Riverside County, CA 97 km (61 mi) ESE earthquakes near Riverside County
San Diego County, CA 115 km (71 mi) S earthquakes near San Diego County
San Bernardino County, CA 117 km (73 mi) NE earthquakes near San Bernardino County
Los Angeles County, CA 119 km (74 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

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

  1. 2.3 5km S of Mentone, CA
  2. 2.2 4km NW of Muscoy, CA
  3. 1.5 3km NE of Grand Terrace, CA
  4. 1.6 4km ENE of Big Bear City, CA
  5. 1.5 4km SSW of Redlands, CA
  6. 1.5 12km N of Big Bear City, CA
  7. 2.6 12km N of Big Bear City, CA
  8. 1.7 6km NNE of Big Bear City, CA
  9. 1.6 10km N of Big Bear Lake, CA
  10. 1.5 3km ENE of Big Bear City, CA
  11. 2.0 5km ESE of Yucaipa, CA
  12. 2.6 3km ENE of San Jacinto, CA
  13. 1.8 5km S of Devore, CA
  14. 1.5 10km ENE of Cabazon, CA
  15. 1.9 7km ENE of Nuevo, 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.