QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

Earthquake near Wrightwood, CA

No earthquake was likely felt in Wrightwood in the 24 hours to 6:21 am PST (14:21 UTC). The last one was M 1.7, 5 km (3 mi) NW, at 6:36 pm PDT on 22 October 2026, estimated intensity II (weak) in town. Every earthquake near Wrightwood

This page: a magnitude 3.0 earthquake was recorded 9 km (5 mi) west-southwest of Wrightwood, CA, at 11:44 am PDT on 12 October 2018 (18:44 UTC), 5.2 km deep. 9 people have reported feeling it to USGS.

USGS: 9km WSW of Wrightwood, CA

72 km (45 mi) ENE of Los Angeles, CA · 24 km (15 mi) NNE of Glendora, CA

11:44 am PDT, Oct 12, 2018 · · 5.2 km deep · released about 1,100 lb of TNT

Every earthquake near Wrightwood Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 52 kmOrange County 74 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
11:44 am PDT on 12 October 2018 ()
Where
9 km (5 mi) west-southwest of Wrightwood, CA · earthquakes near Wrightwood
Magnitude
M 3.0 (ml)
Depth
5.2 km below the surface
Felt
9 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Los Angeles County, 52 km WSW
Nearest mapped fault
San Gabriel fault, 7 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 1610 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 39 km (24 mi) from the epicentre. In Wrightwood, 9 km away, the estimate is intensity III (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: Wrightwood 9 km, intensity III · Phelan 17 km, intensity III · Glendora 26 km, intensity II · La Verne 27 km, intensity II · San Dimas 27 km, intensity II · Claremont 27 km, intensity II · Upland 28 km, intensity II · Azusa 28 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 300,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 13,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 9,400× the energy of this one
  4. This earthquake M 3.0 about 1,100 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 4.4 on 2018-08-29 — about 99 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 The 1987 Whittier Narrows, California Earthquake · 45 km SW of this epicentre
  2. 5.8 The 1991 Sierra Madre, California Earthquake · 26 km WSW of this epicentre
  3. 5.5 The 1990 Upland, California Earthquake · 22 km S of this epicentre
  4. 5.4 5km S of Chino Hills, CA · 43 km S of this epicentre
  5. 5.2 3km W of Lytle Creek, CA · 20 km ESE 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 34.3383, -117.7242. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Los Angeles County, CA 52 km (32 mi) WSW earthquakes near Los Angeles County
Orange County, CA 74 km (46 mi) S earthquakes near Orange County
Kern County, CA 145 km (90 mi) NW earthquakes near Kern County

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

Aftershocks so far

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

  1. 1.7 3km S of Devore, CA
  2. 2.4 2km SSW of Lytle Creek, CA
  3. 1.5 3km SW of San Bernardino, CA
  4. 2.2 5km N of Glen Avon, CA
  5. 2.6 3km NNW of Fontana, CA
  6. 1.7 4km E of Brea, CA
  7. 1.7 3km SW of San Bernardino, CA
  8. 2.4 3km SW of San Bernardino, CA
  9. 2.3 6km SSW of Pearblossum, CA
  10. 3.1 3km NNE of Yorba Linda, CA
  11. 2.6 2km WNW of Adelanto, CA
  12. 1.9 5km S of Rancho Cucamonga, CA
  13. 2.5 3km N of Muscoy, CA
  14. 1.7 7km NNE of San Dimas, CA
  15. 2.3 7km NNE of San Dimas, 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.