QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

11km NW of Rancho Cucamonga, CA

· 2.4 km deep · released about 1,900 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 56 kmOrange County 60 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 3.2 (ml)
Depth
2.4 km below the surface
Felt
205 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Los Angeles County, 56 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2122 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 205 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× 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 34.2033, -117.6537. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Los Angeles County, CA 56 km (35 mi) E of here earthquakes near Los Angeles County
Orange County, CA 60 km (37 mi) N of here earthquakes near Orange County

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

Aftershocks so far

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

  1. 1.6 5km SSW of Redlands, CA
  2. 1.8 1km ENE of Loma Linda, CA
  3. 1.5 6km S of Littlerock, CA
  4. 1.8 4km SE of Loma Linda, CA
  5. 1.8 1km ESE of Loma Linda, CA
  6. 1.7 2km E of Loma Linda, CA
  7. 2.9 2km E of Loma Linda, CA
  8. 3.1 7km SSE of Littlerock, CA
  9. 2.0 1km ENE of Loma Linda, CA
  10. 1.6 4km WSW of Pinon Hills, CA
  11. 1.5 6km NNW of Lytle Creek, CA
  12. 1.9 3km ESE of Loma Linda, CA
  13. 3.4 3km ESE of Loma Linda, CA
  14. 2.2 1km N of Loma Linda, CA
  15. 1.6 1km ENE of Redlands, 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 100 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.