QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

2km SE of Brea, CA

· 9.2 km deep · released about 37 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 27 kmLos Angeles County 47 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
9.2 km below the surface
Felt
5 reports · strongest reported intensity III
Nearest
Orange County, 27 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3421 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 5 people have reported feeling it to USGS.

How big was it?

This earthquake released about 37 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 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 33.9058, -117.8845. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 27 km (17 mi) NNW of here earthquakes near Orange County
Los Angeles County, CA 47 km (29 mi) SE of here earthquakes near Los Angeles County
Ventura County, CA 125 km (78 mi) ESE of here earthquakes near Ventura County
San Diego County, CA 142 km (88 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

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

  1. 1.7 0km SSE of View Park-Windsor Hills, CA
  2. 1.9 4km SE of Home Gardens, CA
  3. 1.7 6km WSW of Huntington Beach, CA
  4. 1.6 7km SSE of Home Gardens, CA
  5. 2.7 7km S of Lytle Creek, CA
  6. 2.0 5km NNW of Yorba Linda, CA
  7. 2.3 1km SW of Mira Loma, CA
  8. 1.8 4km S of Charter Oak, CA
  9. 1.6 2km WSW of San Pedro, CA
  10. 1.5 2km SSW of Huntington Beach, CA
  11. 2.6 4km NNW of Fontana, CA
  12. 2.1 2km S of Placentia, CA
  13. 1.7 2km ESE of Villa Park, CA
  14. 1.7 2km E of Brea, CA
  15. 2.0 10km W of Corona, 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.