QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

3 km NNE of Fontana, California

· 4.4 km deep · released about 9.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 60 kmLos Angeles County 78 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 1.7 (ml)
Depth
4.4 km below the surface
Felt
no reports yet
Nearest
Orange County, 60 km SSW
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.

How big was it?

This earthquake released about 9.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 34.1237, -117.4180. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 60 km (37 mi) NNE of here earthquakes near Orange County
Los Angeles County, CA 78 km (49 mi) E of here earthquakes near Los Angeles County
San Bernardino County, CA 140 km (87 mi) SW of here earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 2.0 0km SW of Colton, CA
  2. 2.3 7km WSW of Pinon Hills, CA
  3. 1.7 2km ESE of Villa Park, CA
  4. 1.7 2km E of Brea, CA
  5. 1.5 7km WSW of Pinon Hills, CA
  6. 2.0 10km W of Corona, CA
  7. 1.9 7km NW of Banning, CA
  8. 1.8 4km SE of Home Gardens, CA
  9. 2.1 1km SSW of Redlands, CA
  10. 3.0 4km SW of Pinon Hills, CA
  11. 1.7 3km SE of Home Gardens, CA
  12. 1.6 5km SSW of Lytle Creek, CA
  13. 1.6 2km SE of Loma Linda, CA
  14. 2.9 4km SE of Grand Terrace, CA
  15. 1.8 3km N of Colton, 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.