QuakeIndex

Earthquake · reviewed by a seismologist

M 4.1mw

8km WSW of Ludlow, CA

Yes. A magnitude 4.1 earthquake was recorded 8km WSW of Ludlow, CA, at 7:32 am PST on 24 January 2016 (15:32 UTC), 2.6 km deep. 145 people have reported feeling it to USGS.

· 2.6 km deep · released about 22 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Bernardino County 18 kmRiverside County 110 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
Magnitude
M 4.1 (mw)
Depth
2.6 km below the surface
Felt
145 reports · strongest reported intensity IV
Measured shaking
intensity VI (ShakeMap)
USGS impact alert
green
Nearest
San Bernardino County, 18 km NNE
Nearest mapped fault
Pisgah-Bullion fault, 14 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 2366 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 105 km (65 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.

How big was it?

This earthquake released about 22 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 7,700× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 340× the energy of this one
  3. Magna, Utah 2020 M 5.7 240× the energy of this one
  4. This earthquake M 4.1 about 22 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 46× 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 (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.

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

  1. 7.1 The 1999 Hector Mine, California Earthquake · 11 km SSW of this epicentre
  2. 6.5 The 1947 Manix, California Earthquake · 41 km NW of this epicentre
  3. 5.8 13km WSW of Ludlow, CA · 5 km WSW of this epicentre
  4. 5.5 17km WSW of Amboy, CA · 37 km SE of this epicentre
  5. 5.4 26km NNW of Yucca Valley, CA · 47 km SSW 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 34.6972, -116.2392. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Bernardino County, CA 18 km (11 mi) NNE earthquakes near San Bernardino County
Riverside County, CA 110 km (68 mi) SSE earthquakes near Riverside County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 1.7 14km SW of Ludlow, CA
  2. 1.7 35km N of Yucca Valley, CA
  3. 1.6 28km NNW of Twentynine Palms, CA
  4. 1.8 36km NE of Lucerne Valley, CA
  5. 1.9 25km WNW of Ludlow, CA
  6. 1.8 25km WNW of Ludlow, CA
  7. 1.9 8km WSW of Ludlow, CA
  8. 2.5 25km WNW of Ludlow, CA
  9. 2.1 28km NNW of Twentynine Palms, CA
  10. 2.4 25km WNW of Ludlow, CA
  11. 1.6 26km WNW of Ludlow, CA
  12. 1.6 26km WNW of Ludlow, CA
  13. 2.6 25km WNW of Ludlow, CA
  14. 1.9 25km WNW of Ludlow, CA
  15. 1.9 9km WSW of Ludlow, 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.