QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Muscoy, CA

No earthquake was likely felt in Muscoy in the 24 hours to 10:56 pm PST (06:56 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 1.6 earthquake was recorded 4 km (3 mi) west-northwest of Muscoy, CA, at 10:16 pm PST on 29 December 2017 (06:16 UTC), 1.7 km deep.

USGS: 4km WNW of Muscoy, CA

6 km (3 mi) N of Rialto, CA · 95 km (59 mi) E of Los Angeles, CA

10:16 pm PST, Dec 29, 2017 · · 1.7 km deep · released about 7.1 lb of TNT

Every earthquake near Muscoy Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 65 kmLos Angeles County 80 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
10:16 pm PST on 29 December 2017 ()
Where
4 km (3 mi) west-northwest of Muscoy, CA · earthquakes near Muscoy
Magnitude
M 1.6 (ml)
Depth
1.7 km below the surface
Felt
no reports yet
Nearest
Orange County, 65 km SSW
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 3228 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 Muscoy, 4 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: Muscoy 4 km, intensity II · Rialto 7 km, intensity II · Fontana 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 7.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.1 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 3 km SE of San Bernardino, California · 15 km SE of this epicentre
  2. 5.6 7km ENE of Running Springs, CA · 33 km ENE of this epicentre
  3. 5.5 The 1990 Upland, California Earthquake · 28 km W of this epicentre
  4. 5.5 11km SSE of Big Bear Lake, California · 50 km E of this epicentre
  5. 5.4 5km S of Chino Hills, CA · 42 km SW 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 34.1672, -117.3903. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 65 km (41 mi) SSW earthquakes near Orange County
Los Angeles County, CA 80 km (50 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 135 km (84 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

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

  1. 1.5 3km SE of Mentone, CA
  2. 1.5 5km SSE of Home Gardens, CA
  3. 1.5 1km NE of Lytle Creek, CA
  4. 1.5 2km WSW of Devore, CA
  5. 2.6 3km ESE of Loma Linda, CA
  6. 1.5 3km ESE of Loma Linda, CA
  7. 1.7 6km SSW of Redlands, CA
  8. 1.5 1km NE of Calimesa, CA
  9. 3.3 3km S of Mentone, CA
  10. 1.7 4km W of Pomona, CA
  11. 2.1 5km SSE of Mentone, CA
  12. 2.2 10km E of Running Springs, CA
  13. 2.2 6km NNE of Fontana, CA
  14. 1.6 3km E of Yucaipa, CA
  15. 1.7 6km NNE of Fontana, 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.