Earthquake · reviewed by a seismologist
M 2.8ml
Earthquake near Ontario, CA
No earthquake was likely felt in Ontario in the 24 hours to 2:41 am PST (10:41 UTC). The last one was M 1.7, 8 km (5 mi) SE, at 2:48 pm PDT on 9 October 2026, estimated intensity II (weak) in town. Every earthquake near Ontario
This page: a magnitude 2.8 earthquake was recorded 8 km (5 mi) southeast of Ontario, CA, at 1:35 pm PDT on 16 August 2026 (20:35 UTC), 5.6 km deep. 128 people have reported feeling it to USGS.
USGS: 6 km SE of Ontario, CA
in Ontario, CA · 76 km (47 mi) E of Los Angeles, CA
- When
- 1:35 pm PDT on 16 August 2026 ()
- Where
- 8 km (5 mi) southeast of Ontario, CA · earthquakes near Ontario
- Magnitude
- M 2.8 (ml)
- Depth
- 5.6 km below the surface
- Felt
- 128 reports · strongest reported intensity IV
- Nearest
- Orange County, 41 km SSW
- Nearest mapped fault
- Red Hill-Etiwanda Avenue fault, 12 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 74 days ago
Earthquake alerts for Ontario, CA
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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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 26 km (16 mi) from the epicentre. In Ontario, 8 km away, the estimate is intensity III (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.
Likely felt in: Eastvale 6 km, intensity III · Ontario 8 km, intensity III · Chino 9 km, intensity III · Norco 10 km, intensity III · Rancho Cucamonga 11 km, intensity III · Upland 11 km, intensity III · Pedley 11 km, intensity III · Montclair 12 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 450 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 34,000× the energy of this one
- Magna, Utah 2020 M 5.7 24,000× the energy of this one
- Around the size people start to feel M 3.0 2.1× the energy of this one
- This earthquake M 2.8 about 450 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 440 times the energy of this one.
Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:
- 6.2 3 km SE of San Bernardino, California · 32 km ENE of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 39 km SSE of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 45 km W of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 47 km NW of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 18 km NW 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 34.0115, -117.5890. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 41 km (26 mi) | SSW | earthquakes near Orange County |
| Los Angeles County, CA | 65 km (41 mi) | WNW | earthquakes near Los Angeles County |
| San Diego County, CA | 133 km (83 mi) | SE | earthquakes near San Diego County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 1.0 6 km WNW of Calimesa, CA
- 1.3 8 km S of Chino Hills, CA
- 1.3 3 km ENE of Fontana, CA
- 0.8 9 km WSW of Beaumont, CA
- 1.0 9 km E of Yorba Linda, CA
- 0.7 8 km NNE of Moreno Valley, CA
- 1.3 3 km SE of Home Gardens, CA
- 1.5 10 km ENE of North Tustin, CA
- 0.7 6 km S of Redlands, CA
- 0.9 6 km S of Redlands, CA
- 0.9 1 km ESE of Home Gardens, CA
- 1.4 5 km NNW of Lake Elsinore, CA
- 1.1 6 km S of Redlands, CA
- 1.1 2 km W of Calimesa, CA
- 0.9 6 km WNW of Calimesa, 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
- 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.