QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Fontana, CA

USGS: 4 km W of Devore, CA

13 km (8 mi) NNW of Rialto, CA · 92 km (57 mi) ENE of Los Angeles, CA

3:16 am PDT, Oct 1, 2026 · · 10 km deep · released about 44 lb of TNT

10 km30 km60 km120 km N Orange County 68 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
3:16 am PDT on 1 October 2026 ()
Where
14 km (9 mi) N of Fontana, CA · earthquakes near Fontana
Magnitude
M 2.1 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Orange County, 68 km SSW
Nearest mapped fault
San Jacinto fault, under 1 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 2 days ago

A magnitude 2.1 earthquake was recorded 14 km (9 mi) N of Fontana, CA, at 3:16 am PDT on 1 October 2026 (10:16 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Muscoy, Rialto, Crestline, Bloomington, Oak Hills, San Bernardino.

How big was it?

This earthquake released about 44 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 2,500 times the energy of this one.

Before 2016, the USGS record lists 10 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 3 km SE of San Bernardino, California · 22 km SE of this epicentre
  2. 5.6 7km ENE of Running Springs, CA · 37 km E of this epicentre
  3. 5.5 The 1990 Upland, California Earthquake · 25 km WSW of this epicentre
  4. 5.4 5km S of Chino Hills, CA · 43 km SW of this epicentre
  5. 5.3 Near San Bernardino, California · 31 km E 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 34.2218, -117.4407. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 68 km (42 mi) SSW earthquakes near Orange County
Los Angeles County, CA 76 km (47 mi) W earthquakes near Los Angeles County
San Bernardino County, CA 135 km (84 mi) ENE earthquakes near San Bernardino County

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

Aftershocks so far

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

  1. 1.0 8 km S of Llano, CA
  2. 1.2 2 km SE of Home Gardens, CA
  3. 1.5 5 km SSE of Home Gardens, CA
  4. 1.3 7 km SSE of Home Gardens, CA
  5. 1.2 4 km N of Rancho Cucamonga, 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.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

What changedFromToWhen
review statusautomaticreviewed
longitude-117.44-117.44
latitude34.2234.22
depth10.3210.39
magnitude2.192.11

On USGS

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