QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Fontana, CA

No earthquake was likely felt in Fontana in the 24 hours to 9:34 am PST (17:34 UTC). The last one was M 1.6, 5 km (3 mi) W, at 6:17 am PDT on 26 October 2026, estimated intensity II (weak) in town. Every earthquake near Fontana

This page: a magnitude 1.5 earthquake was recorded 7 km (4 mi) west of Fontana, CA, at 10:50 am PDT on 4 September 2022 (17:50 UTC), 14 km deep.

USGS: 5km WSW of Fontana, CA

5 km (3 mi) SW of Fontana, CA · 83 km (52 mi) E of Los Angeles, CA

10:50 am PDT, Sep 4, 2022 · · 14 km deep · released about 5.9 lb of TNT

10 km30 km60 km120 km N Orange County 52 kmLos Angeles County 70 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
10:50 am PDT on 4 September 2022 ()
Where
7 km (4 mi) west of Fontana, CA · earthquakes near Fontana
Magnitude
M 1.5 (ml)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Orange County, 52 km SSW
Nearest mapped fault
Red Hill-Etiwanda Avenue fault, 7 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1527 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Fontana, 7 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Rancho Cucamonga, Glen Avon, Jurupa Valley, Sunnyslope, Bloomington, Pedley.

How big was it?

This earthquake released about 5.9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.4 on 2018-08-29 — about 19,000 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 3 km SE of San Bernardino, California · 23 km E of this epicentre
  2. 6.0 The 1910 Lake Elsinore, California Earthquake · 44 km SSE of this epicentre
  3. 5.8 The 1991 Sierra Madre, California Earthquake · 49 km WNW of this epicentre
  4. 5.6 7km ENE of Running Springs, CA · 47 km ENE of this epicentre
  5. 5.5 The 1990 Upland, California Earthquake · 18 km WNW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 34.0828, -117.5112. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 52 km (32 mi) SSW earthquakes near Orange County
Los Angeles County, CA 70 km (44 mi) W earthquakes near Los Angeles County
San Diego County, CA 136 km (85 mi) SSE earthquakes near San Diego County

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

Aftershocks so far

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

  1. 2.3 4km SE of Loma Linda, CA
  2. 2.5 4km SE of Loma Linda, CA
  3. 1.5 3km SSE of Duarte, CA
  4. 1.8 2km E of Loma Linda, CA
  5. 1.9 5km ESE of Lytle Creek, CA
  6. 1.8 2km SE of Loma Linda, CA
  7. 2.2 2km ESE of Loma Linda, CA
  8. 1.8 4km SE of Home Gardens, CA
  9. 2.2 9km SSW of Calimesa, CA
  10. 2.1 8km NNW of Fontana, CA
  11. 1.9 8km WSW of Corona, CA
  12. 2.0 8km E of Yorba Linda, CA
  13. 3.0 6km ESE of Wrightwood, CA
  14. 2.9 2km E of Loma Linda, CA
  15. 1.5 14km NE of Glendora, 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.