Earthquake · reviewed by a seismologist
M 2.5ml
Earthquake near Charter Oak, CA
No earthquake was likely felt in Charter Oak in the 24 hours to 10:41 am PST (18:41 UTC). The last one was M 3.6, 64 km (40 mi) WSW, at 8:40 am PDT on 27 September 2026, estimated intensity II (weak) in town; 1,735 felt reports to USGS. Every earthquake near Charter Oak
This page: a magnitude 2.5 earthquake was recorded 3 km (2 mi) south of Charter Oak, CA, at 5:16 pm PDT on 6 August 2024 (00:16 UTC), 12 km deep. 37 people have reported feeling it to USGS.
USGS: 3 km S of Charter Oak, CA
6 km (4 mi) ENE of West Covina, CA · 53 km (33 mi) E of Los Angeles, CA
- When
- 5:16 pm PDT on 6 August 2024 ()
- Where
- 3 km (2 mi) south of Charter Oak, CA · earthquakes near Charter Oak
- Magnitude
- M 2.5 (ml)
- Depth
- 12 km below the surface
- Felt
- 37 reports · strongest reported intensity IV
- Nearest
- Los Angeles County, 41 km WNW
- Nearest mapped fault
- Sierra Madre 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 469 days ago
Earthquake alerts for Charter Oak, 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 19 km (12 mi) from the epicentre. In Charter Oak, 3 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.
Likely felt in: Covina 5 km, intensity II · San Dimas 5 km, intensity II · Diamond Bar 6 km, intensity II · Walnut 6 km, intensity II · Glendora 7 km, intensity II · La Verne 8 km, intensity II · Pomona 9 km, intensity II · West Covina 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
- Magna, Utah 2020 M 5.7 63,000× the energy of this one
- Around the size people start to feel M 3.0 5.6× the energy of this one
- This earthquake M 2.5 about 170 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 1,100 times the energy of this one.
Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:
- 5.9 The 1987 Whittier Narrows, California Earthquake · 22 km W of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 26 km NNW of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 16 km ENE of this epicentre
- 5.4 5km S of Chino Hills, CA · 16 km SSE of this epicentre
- 5.2 3km W of Lytle Creek, CA · 35 km NE 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 34.0747, -117.8437. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Los Angeles County, CA | 41 km (25 mi) | WNW | earthquakes near Los Angeles County |
| Orange County, CA | 45 km (28 mi) | S | earthquakes near Orange County |
| Ventura County, CA | 123 km (76 mi) | WNW | earthquakes near Ventura County |
| San Diego County, CA | 153 km (95 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
56 earthquakes have been recorded within 50 km since this one.
- 1.6 4 km SSE of Highland Park, CA
- 1.8 5 km SE of Ontario, CA
- 1.7 5 km SE of Ontario, CA
- 1.8 5 km SE of Ontario, CA
- 2.5 8 km E of Yorba Linda, CA
- 1.9 5 km SE of Ontario, CA
- 1.6 4 km SE of Ontario, CA
- 1.6 5 km SE of Ontario, CA
- 1.7 5 km SE of Ontario, CA
- 2.6 4 km SE of Ontario, CA
- 2.2 4 km SE of Ontario, CA
- 2.0 4 km SE of Ontario, CA
- 2.1 5 km SE of Ontario, CA
- 2.2 5 km SE of Ontario, CA
- 2.0 5 km SE of Ontario, 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.