QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Signal Hill, CA

No earthquake was likely felt in Signal Hill in the 24 hours to 3:50 pm PST (23:50 UTC). The last one was M 3.2, 2 km (2 mi) SW, at 12:44 am PDT on 9 October 2026, estimated intensity III (weak) in town; 1,090 felt reports to USGS. Every earthquake near Signal Hill

This page: a magnitude 1.8 earthquake was recorded 6 km (4 mi) northwest of Signal Hill, CA, at 1:34 pm PDT on 11 April 2018 (20:34 UTC), 12 km deep.

USGS: 6km NW of Signal Hill, CA

27 km (17 mi) SE of Los Angeles, CA · in Carson, CA

1:34 pm PDT, Apr 11, 2018 · · 12 km deep · released about 14 lb of TNT

Every earthquake near Signal Hill Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 40 kmOrange County 44 kmVentura County 102 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
1:34 pm PDT on 11 April 2018 ()
Where
6 km (4 mi) northwest of Signal Hill, CA · earthquakes near Signal Hill
Magnitude
M 1.8 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 40 km N
Nearest mapped fault
Palos Verdes fault, 10 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 3031 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 6 km (4 mi) from the epicentre. In Signal Hill, 6 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: Signal Hill 6 km, intensity II · Carson 6 km, intensity II · Compton 6 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 14 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1933 Long Beach, California Earthquake · 31 km SE of this epicentre
  2. 5.9 The 1987 Whittier Narrows, California Earthquake · 28 km NNE of this epicentre
  3. 5.4 5km S of Chino Hills, CA · 43 km ENE of this epicentre
  4. 5.3 2 km SSW of Santa Monica, California · 32 km NW of this epicentre
  5. 5.3 7km W of Newport Beach, CA · 31 km SE 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 33.8383, -118.2167. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Los Angeles County, CA 40 km (25 mi) N earthquakes near Los Angeles County
Orange County, CA 44 km (28 mi) ESE earthquakes near Orange County
Ventura County, CA 102 km (64 mi) NW earthquakes near Ventura County

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

Aftershocks so far

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

  1. 1.6 1km ENE of Lennox, CA
  2. 1.6 12km SSE of San Pedro, CA
  3. 2.5 2km NE of Villa Park, CA
  4. 1.7 1km ENE of Yorba Linda, CA
  5. 2.3 3km SSE of Charter Oak, CA
  6. 1.6 1km SSE of Placentia, CA
  7. 2.6 3km SSW of Signal Hill, CA
  8. 1.9 2km WSW of Yorba Linda, CA
  9. 1.5 4km SE of Rancho Palos Verdes, CA
  10. 1.6 0km ENE of Universal City, CA
  11. 1.6 22km N of Avalon, CA
  12. 1.6 12km SW of Marina del Rey, CA
  13. 2.9 2km S of Buena Park, CA
  14. 2.0 4km SSW of Baldwin Hills, CA
  15. 1.8 4km WSW of Irvine, 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.