QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Seal Beach, CA

No earthquake was likely felt in Seal Beach in the 24 hours to 3:52 pm PST (23:52 UTC). The last one was M 3.2, 9 km (6 mi) NW, at 12:44 am PDT on 9 October 2026, estimated intensity III (weak) in town; 1,090 felt reports to USGS. Every earthquake near Seal Beach

This page: a magnitude 1.8 earthquake was recorded 22 km (14 mi) south-southwest of Seal Beach, CA, at 1:08 pm PST on 29 December 2021 (21:08 UTC), 2.1 km deep.

USGS: 22km SSW of Seal Beach, CA

56 km (35 mi) SSE of Los Angeles, CA · 23 km (14 mi) SW of Huntington Beach, CA

1:08 pm PST, Dec 29, 2021 · · 2.1 km deep · released about 15 lb of TNT

Every earthquake near Seal Beach Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 40 kmLos Angeles County 72 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
1:08 pm PST on 29 December 2021 ()
Where
22 km (14 mi) south-southwest of Seal Beach, CA · earthquakes near Seal Beach
Magnitude
M 1.8 (ml)
Depth
2.1 km below the surface
Felt
no reports yet
Nearest
Orange County, 40 km ENE
Nearest mapped fault
Palos Verdes fault, 5 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 1758 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 13 km (8 mi) from the epicentre. In Seal Beach, 22 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.

Earthquakes near other towns within 30 km: Huntington Beach, Long Beach, Newport Beach, Costa Mesa, Avalon, Fountain Valley.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 4.3 on 2021-09-18 — about 5,200 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1933 Long Beach, California Earthquake · 19 km ENE of this epicentre
  2. 5.3 7km W of Newport Beach, CA · 18 km ENE of this epicentre
  3. 5.1 The 1941 Torrance-Gardena, California Earthquakes (Second Event) · 28 km NNW of this epicentre
  4. 5.1 2km NW of Brea, CA · 49 km NNE of this epicentre
  5. 5.0 2km ENE of Westminster, CA · 30 km NE 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 33.5525, -118.1805. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 40 km (25 mi) ENE earthquakes near Orange County
Los Angeles County, CA 72 km (45 mi) N earthquakes near Los Angeles County
Ventura County, CA 126 km (78 mi) NW earthquakes near Ventura County

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

Aftershocks so far

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

  1. 2.1 4km S of Huntington Beach, CA
  2. 1.9 4km N of Fountain Valley, CA
  3. 1.7 5km WNW of Huntington Beach, CA
  4. 2.3 17km SSE of San Pedro, CA
  5. 1.6 17km SSE of San Pedro, CA
  6. 1.5 4km ENE of Hawthorne, CA
  7. 2.0 4km N of Gardena, CA
  8. 1.7 4km ESE of Lennox, CA
  9. 1.7 4km ESE of Lennox, CA
  10. 1.7 3km N of Gardena, CA
  11. 1.8 4km N of Gardena, CA
  12. 2.0 3km ESE of Villa Park, CA
  13. 2.1 21km SSW of San Pedro, CA
  14. 1.5 3km ESE of Carson, CA
  15. 1.5 2km NE of La Habra, 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.