QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

4km NNW of Seal Beach, CA

· 15 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Orange County 34 kmLos Angeles County 49 kmVentura County 114 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 1.8 (ml)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Orange County, 34 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3518 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

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 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× 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.

Where

Epicentre 33.7698, -118.1242. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 34 km (21 mi) WNW of here earthquakes near Orange County
Los Angeles County, CA 49 km (31 mi) SSE of here earthquakes near Los Angeles County
Ventura County, CA 114 km (71 mi) SE of here earthquakes near Ventura County

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

Aftershocks so far

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

  1. 1.6 2km WSW of San Pedro, CA
  2. 1.5 2km SSW of Huntington Beach, CA
  3. 2.1 2km S of Placentia, CA
  4. 1.7 2km ESE of Villa Park, CA
  5. 1.7 2km E of Brea, CA
  6. 2.0 10km W of Corona, CA
  7. 2.3 5km W of El Segundo, CA
  8. 1.6 2km W of Fountain Valley, CA
  9. 1.9 2km SE of Carson, CA
  10. 1.8 2km S of Sherman Oaks, CA
  11. 1.5 2km NNW of Silver Lake, CA
  12. 1.7 1km E of Alhambra, CA
  13. 2.5 7km E of Yorba Linda, CA
  14. 1.6 12km SSW of Rancho Palos Verdes, CA
  15. 1.9 3km E of Gardena, 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.