QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Earthquake near Muscoy, CA

No earthquake was likely felt in Muscoy in the 24 hours to 12:34 pm PST (20:34 UTC). The last one was M 2.2, 17 km (10 mi) SE, at 8:15 pm PDT on 29 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Muscoy

This page: a magnitude 3.3 earthquake was recorded in Muscoy, CA, at 11:32 pm PDT on 8 May 2026 (06:32 UTC), 13 km deep. 592 people have reported feeling it to USGS.

USGS: 1 km SE of Muscoy, CA

in San Bernardino, CA

11:32 pm PDT, May 8, 2026 · · 13 km deep · released about 1.3 tons of TNT

Every earthquake near Muscoy Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 66 kmLos Angeles County 85 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
11:32 pm PDT on 8 May 2026 ()
Where
in Muscoy, CA · earthquakes near Muscoy
Magnitude
M 3.3 (ml)
Depth
13 km below the surface
Felt
592 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Orange County, 66 km SW
Nearest mapped fault
San Jacinto 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 117 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 50 km (31 mi) from the epicentre. 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: Muscoy in town, intensity III · Rialto 6 km, intensity III · San Bernardino 6 km, intensity III · Colton 8 km, intensity III · Fontana 11 km, intensity III · Highland 12 km, intensity III · Loma Linda 13 km, intensity III · Redlands 17 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,800× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,100× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.7× more

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 45 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.3 The 1992 Big Bear, California Earthquake · 47 km E of this epicentre
  2. 6.2 3 km SE of San Bernardino, California · 10 km SE of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 29 km ENE of this epicentre
  4. 5.5 The 1990 Upland, California Earthquake · 33 km W of this epicentre
  5. 5.5 11km SSE of Big Bear Lake, California · 45 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 34.1478, -117.3355. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 66 km (41 mi) SW earthquakes near Orange County
Los Angeles County, CA 85 km (53 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 132 km (82 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 6 km SSE of Big Bear Lake, CA
  2. 1.8 10 km NNW of Banning, CA
  3. 2.2 6 km NNW of Beaumont, CA
  4. 1.7 2 km NW of Banning, CA
  5. 1.7 8 km WNW of Big Bear Lake, CA
  6. 1.5 5 km SE of Big Bear Lake, CA
  7. 2.0 3 km ENE of Running Springs, CA
  8. 1.5 3 km ENE of Running Springs, CA
  9. 1.7 4 km SE of Home Gardens, CA
  10. 1.5 7 km SSE of Home Gardens, CA
  11. 2.2 6 km SSE of Big Bear Lake, CA
  12. 1.6 6 km NNE of Fontana, CA
  13. 1.9 3 km WSW of Lytle Creek, CA
  14. 1.6 3 km NNW of Colton, CA
  15. 2.1 2 km NNW 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.