QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

1km SE of South Gate, CA

· 16 km deep · released about 1.2 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 28 kmOrange County 50 kmVentura County 97 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 3.3 (ml)
Depth
16 km below the surface
Felt
1137 reports · strongest reported intensity III
Measured shaking
intensity IV (ShakeMap)
Nearest
Los Angeles County, 28 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 10 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1137 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 140,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,500× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,600× the energy of this one
  4. This earthquake M 3.3 about 1.2 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.5× 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.

Where

Epicentre 33.9490, -118.2048. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Los Angeles County, CA 28 km (17 mi) S of here earthquakes near Los Angeles County
Orange County, CA 50 km (31 mi) NW of here earthquakes near Orange County
Ventura County, CA 97 km (60 mi) ESE 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. 1.8 12km WSW of Newport Beach, CA
  2. 1.6 7km S of Huntington Beach, CA
  3. 1.7 6km S of Huntington Beach, CA
  4. 2.4 7km S of Huntington Beach, CA
  5. 1.8 7km S of Huntington Beach, CA
  6. 1.7 3km SW of Orange, CA
  7. 1.6 7km S of Newport Beach, CA
  8. 1.8 2km W of Lakewood, CA
  9. 1.6 3km SE of South Whittier, CA
  10. 1.9 17km SSE of San Pedro, CA
  11. 2.1 4km S of Huntington Beach, CA
  12. 1.9 4km N of Fountain Valley, CA
  13. 1.7 5km WNW of Huntington Beach, CA
  14. 2.3 17km SSE of San Pedro, CA
  15. 1.7 8km ESE of Yorba Linda, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2020-09-19 — it released about 83 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.