QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

3km E of Norco, CA

· 3.1 km deep · released about 47 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 37 kmLos Angeles County 75 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
3.1 km below the surface
Felt
137 reports · strongest reported intensity IV
Nearest
Orange County, 37 km SW
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. 137 people have reported feeling it to USGS.

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 33.9292, -117.5120. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 37 km (23 mi) NE of here earthquakes near Orange County
Los Angeles County, CA 75 km (47 mi) ESE of here earthquakes near Los Angeles County
San Diego County, CA 122 km (76 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. 1.8 2km NE of Redlands, CA
  2. 1.6 8km ESE of Yorba Linda, CA
  3. 1.6 3km SE of Loma Linda, CA
  4. 2.6 3km SE of Loma Linda, CA
  5. 1.6 3km ESE of Loma Linda, CA
  6. 2.7 5km E of Calimesa, CA
  7. 2.7 2km ESE of Loma Linda, CA
  8. 1.5 5km ENE of Rancho Cucamonga, CA
  9. 1.5 3km ESE of Loma Linda, CA
  10. 2.5 10km N of Lytle Creek, CA
  11. 1.7 5km NE of Yorba Linda, CA
  12. 2.3 1km NNW of Colton, CA
  13. 1.9 5km SSE of Home Gardens, CA
  14. 2.2 4km SE of Yucaipa, CA
  15. 2.4 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.