QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

4 km WSW of Alhambra, CA

· 11 km deep · released about 480 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 16 kmOrange County 58 kmVentura County 94 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 2.8 (ml)
Depth
11 km below the surface
Felt
261 reports · strongest reported intensity III
Nearest
Los Angeles County, 16 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 193 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 261 people have reported feeling it to USGS.

How big was it?

This earthquake released about 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 34.0827, -118.1637. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Los Angeles County, CA 16 km (10 mi) SE of here earthquakes near Los Angeles County
Orange County, CA 58 km (36 mi) NW of here earthquakes near Orange County
Ventura County, CA 94 km (59 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. 1.6 3 km SSW of Yorba Linda, CA
  2. 1.7 1 km N of Universal City, CA
  3. 2.7 7 km SW of Seal Beach, CA
  4. 1.8 1 km NE of Sherman Oaks, CA
  5. 1.6 7 km S of Las Flores, CA
  6. 1.6 5 km ESE of Yorba Linda, CA
  7. 1.8 3 km SSE of Cudahy, CA
  8. 2.0 1 km E of Palos Verdes Estates, CA
  9. 1.6 1 km NW of Rolling Hills Estates, CA
  10. 1.8 3 km NE of Vincent, CA
  11. 1.6 3 km N of Placentia, CA
  12. 2.1 5 km ESE of Yorba Linda, CA
  13. 1.7 2 km N of Universal City, CA
  14. 1.6 4 km SE of Rowland Heights, CA
  15. 1.6 2 km NNW of Universal City, 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 410 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.