QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

2km S of Placentia, CA

· 12 km deep · released about 47 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 21 kmLos Angeles County 53 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 2.1 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Orange County, 21 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3258 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 47 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 320,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 20× the energy of this one
  4. This earthquake M 2.1 about 47 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 33.8508, -117.8703. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 21 km (13 mi) NNW of here earthquakes near Orange County
Los Angeles County, CA 53 km (33 mi) SE of here earthquakes near Los Angeles County
Ventura County, CA 129 km (80 mi) ESE of here earthquakes near Ventura County
San Diego County, CA 137 km (85 mi) NW of here earthquakes near San Diego County

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

Aftershocks so far

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

  1. 1.6 8km ESE of Yorba Linda, CA
  2. 1.5 5km ENE of Rancho Cucamonga, CA
  3. 3.1 5km WNW of Willowbrook, CA
  4. 2.1 5km WNW of Willowbrook, CA
  5. 1.6 4km N of Gardena, CA
  6. 1.7 12km SSE of San Pedro, CA
  7. 1.6 11km S of San Pedro, CA
  8. 1.8 3km WSW of East Los Angeles, CA
  9. 1.7 5km NE of Yorba Linda, CA
  10. 1.9 5km SSE of Home Gardens, CA
  11. 2.4 4km SSW of Yorba Linda, CA
  12. 1.6 7km WSW of Huntington Beach, CA
  13. 2.1 4km SSW of Yorba Linda, CA
  14. 1.6 4km ESE of Placentia, CA
  15. 1.6 4km SSW 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.

On USGS

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