QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7mw

13km NE of Ludlow, CA

Yes. A magnitude 3.7 earthquake was recorded 13km NE of Ludlow, CA, at 11:56 am PST on 14 January 2018 (19:56 UTC), 3.8 km deep. 19 people have reported feeling it to USGS.

· 3.8 km deep · released about 5.5 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Bernardino County 11 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 3.7 (mw)
Depth
3.8 km below the surface
Felt
19 reports · strongest reported intensity III
Measured shaking
intensity VI (ShakeMap)
Nearest
San Bernardino County, 11 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1588 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 76 km (47 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 5.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 31,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 970× the energy of this one
  4. This earthquake M 3.7 about 5.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 12× 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 4.1 on 2016-01-24 — about 4 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.1 The 1999 Hector Mine, California Earthquake · 30 km SW of this epicentre
  2. 6.5 The 1947 Manix, California Earthquake · 46 km WNW of this epicentre
  3. 5.8 13km WSW of Ludlow, CA · 25 km SW of this epicentre
  4. 5.5 17km WSW of Amboy, CA · 38 km SSE of this epicentre
  5. 5.4 21km SW of Ludlow, California · 35 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 34.8168, -116.0733. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Bernardino County, CA 11 km (7 mi) WNW earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 3.2 11km W of Ludlow, CA
  2. 1.7 11km W of Ludlow, CA
  3. 1.8 13km W of Ludlow, CA
  4. 1.7 28km SSW of Ludlow, CA
  5. 1.8 14km WSW of Ludlow, CA
  6. 1.8 12km WSW of Ludlow, CA
  7. 1.8 32km SSW of Ludlow, CA
  8. 1.8 16km WSW of Ludlow, CA
  9. 1.7 14km WSW of Ludlow, CA
  10. 2.0 14km WSW of Ludlow, CA
  11. 1.9 35km WSW of Ludlow, CA
  12. 1.7 24km W of Ludlow, CA
  13. 1.8 24km SSW of Ludlow, CA
  14. 1.8 15km NW of Ludlow, CA
  15. 1.9 14km NW 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.