Earthquake · reviewed by a seismologist
M 1.0ml
Earthquake near Rancho Cucamonga, CA
No earthquake was likely felt in Rancho Cucamonga in the 24 hours to 4:07 pm PDT (23:07 UTC). The last one was M 1.7, 10 km (6 mi) S, at 2:48 pm PDT on 9 October 2026, estimated intensity II (weak) in town. Every earthquake near Rancho Cucamonga
This page: a magnitude 1.0 earthquake was recorded 10 km (6 mi) north of Rancho Cucamonga, CA, at 7:47 pm PDT on 17 October 2026 (02:47 UTC), 3.9 km deep.
USGS: 8 km N of Rancho Cucamonga, CA
7 km (5 mi) NNW of Rancho Cucamonga, CA · 79 km (49 mi) ENE of Los Angeles, CA
- When
- 7:47 pm PDT on 17 October 2026 ()
- Where
- 10 km (6 mi) north of Rancho Cucamonga, CA · earthquakes near Rancho Cucamonga
- Magnitude
- M 1.0 (ml)
- Depth
- 3.9 km below the surface
- Felt
- no reports yet
- Nearest
- Orange County, 61 km SSW
- Nearest mapped fault
- San Jacinto fault, 2 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 3 days ago
Earthquake alerts for Rancho Cucamonga, CA
Get a notification in this browser when USGS records an earthquake near Rancho Cucamonga, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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. 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: San Antonio Heights, Upland, Ontario, Montclair, Claremont, Fontana.
How big was it?
This earthquake released about 0.86 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.0 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 18,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 12,000,000× the energy of this one
- Around the size people start to feel M 3.0 1,100× the energy of this one
- This earthquake M 1.0 about 0.86 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 4.5 on 2020-09-19 — about 230,000 times the energy of this one.
Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:
- 6.2 3 km SE of San Bernardino, California · 32 km ESE of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 48 km WSW of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 39 km WNW of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 12 km WSW of this epicentre
- 5.4 5km S of Chino Hills, CA · 32 km SSW 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 34.1955, -117.5823. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 61 km (38 mi) | SSW | earthquakes near Orange County |
| Los Angeles County, CA | 62 km (39 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
12 earthquakes have been recorded within 50 km since this one.
- 1.6 3 km SE of Home Gardens, CA
- 1.0 7 km NNE of Fontana, CA
- 1.0 8 km ENE of Moreno Valley, CA
- 1.2 5 km NE of Bradbury, CA
- 1.3 3 km SE of Loma Linda, CA
- 1.3 3 km SE of Loma Linda, CA
- 2.4 1 km E of Loma Linda, CA
- 0.6 1 km NW of Covina, CA
- 0.9 2 km SE of Loma Linda, CA
- 1.6 1 km SSE of Loma Linda, CA
- 0.7 4 km NNE of Moreno Valley, CA
- 0.9 4 km NNE of Moreno Valley, 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 changed | From | To | When |
|---|---|---|---|
| review status | automatic | reviewed |
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.