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 1:47 pm PST (21:47 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 13 km (8 mi) north-northwest of Fontana, CA, at 8:46 pm PDT on 20 August 2022 (03:46 UTC), 4.7 km deep.

USGS: 7km S of Lytle Creek, CA

10 km (6 mi) NNW of Fontana, CA · 87 km (54 mi) ENE of Los Angeles, CA

8:46 pm PDT, Aug 20, 2022 · · 4.7 km deep · released about 6.2 lb of TNT

Every earthquake near Fontana Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 64 kmLos Angeles County 71 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
8:46 pm PDT on 20 August 2022 ()
Where
13 km (8 mi) north-northwest of Fontana, CA · earthquakes near Fontana
Magnitude
M 1.5 (ml)
Depth
4.7 km below the surface
Felt
no reports yet
Nearest
Orange County, 64 km SSW
Nearest mapped fault
San Jacinto fault, 3 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 1543 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Fontana, 13 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: Muscoy, Rancho Cucamonga, Rialto, San Antonio Heights, Bloomington, Upland.

How big was it?

This earthquake released about 6.2 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 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 18,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 3 km SE of San Bernardino, California · 24 km ESE of this epicentre
  2. 5.8 The 1991 Sierra Madre, California Earthquake · 47 km W of this epicentre
  3. 5.6 7km ENE of Running Springs, CA · 41 km E of this epicentre
  4. 5.5 The 1990 Upland, California Earthquake · 20 km WSW of this epicentre
  5. 5.4 5km S of Chino Hills, CA · 38 km SW 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 34.1980, -117.4862. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 64 km (40 mi) SSW earthquakes near Orange County
Los Angeles County, CA 71 km (44 mi) W earthquakes near Los Angeles 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. 2.0 8km E of Yorba Linda, CA
  2. 3.0 6km ESE of Wrightwood, CA
  3. 2.9 2km E of Loma Linda, CA
  4. 1.5 14km NE of Glendora, CA
  5. 1.8 4km SSE of Home Gardens, CA
  6. 2.1 9km NW of Adelanto, CA
  7. 1.6 1km ESE of Loma Linda, CA
  8. 1.6 4km SSW of Llano, CA
  9. 1.9 2km ESE of Colton, CA
  10. 1.5 7km SSE of Home Gardens, CA
  11. 2.2 3km ESE of Loma Linda, CA
  12. 1.5 5km SE of Home Gardens, CA
  13. 2.5 4km SE of Loma Linda, CA
  14. 2.0 4km SE of Loma Linda, CA
  15. 2.2 5km SSW 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.