QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

7km NNE of Fontana, CA

· 9.5 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 62 kmLos Angeles County 76 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 1.8 (ml)
Depth
9.5 km below the surface
Felt
no reports yet
Nearest
Orange County, 62 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2210 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 34.1618, -117.4410. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 62 km (39 mi) NNE of here earthquakes near Orange County
Los Angeles County, CA 76 km (47 mi) E of here earthquakes near Los Angeles County
San Bernardino County, CA 139 km (86 mi) WSW 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

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

  1. 1.5 3km WSW of Redlands, CA
  2. 1.5 2km NNW of Fontana, CA
  3. 1.6 2km W of Calimesa, CA
  4. 2.0 4km NNE of Walnut, CA
  5. 1.7 7km N of Fontana, CA
  6. 1.5 5km SE of Lytle Creek, CA
  7. 1.8 6km SSW of Calimesa, CA
  8. 1.6 15km NW of Rancho Cucamonga, CA
  9. 1.6 10km SSW of Calimesa, CA
  10. 2.6 6km NW of Corona, CA
  11. 1.6 6km NW of Corona, CA
  12. 1.9 6km NW of Corona, CA
  13. 1.5 4km SW of Redlands, CA
  14. 1.6 4km SW of Redlands, CA
  15. 1.5 13km NNE of Yucaipa, 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 4.4 on 2018-08-29 — it released about 7,400 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.