Earthquake · reviewed by a seismologist
M 2.1ml
Earthquake near Placentia, CA
No earthquake was likely felt in Placentia in the 24 hours to 4:39 am PST (12:39 UTC). The last one was M 3.2, 31 km (19 mi) WSW, at 12:44 am PDT on 9 October 2026, estimated intensity II (weak) in town; 1,090 felt reports to USGS. Every earthquake near Placentia
This page: a magnitude 2.1 earthquake was recorded 2 km (1 mi) south of Placentia, CA, at 12:24 pm PDT on 15 July 2017 (19:24 UTC), 12 km deep.
USGS: 2km S of Placentia, CA
in Placentia, CA · 53 km (33 mi) ESE of Los Angeles, CA
- When
- 12:24 pm PDT on 15 July 2017 ()
- Where
- 2 km (1 mi) south of Placentia, CA · earthquakes near Placentia
- Magnitude
- M 2.1 (ml)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Orange County, 21 km SSE
- Nearest mapped fault
- Puente Hills blind thrust system, 4 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 3305 days ago
Earthquake alerts for Placentia, CA
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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, people at rest would likely notice it out to about 13 km (8 mi) from the epicentre. In Placentia, 2 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: Placentia 2 km, intensity II · Anaheim 4 km, intensity II · Fullerton 6 km, intensity II · Yorba Linda 7 km, intensity II · Orange 7 km, intensity II · Brea 8 km, intensity II · Garden Grove 11 km, intensity II · La Habra 11 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 47 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.
- Mineral, Virginia 2011 M 5.8 320,000× the energy of this one
- Magna, Utah 2020 M 5.7 230,000× the energy of this one
- Around the size people start to feel M 3.0 20× the energy of this one
- This earthquake M 2.1 about 47 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:
- 6.4 The 1933 Long Beach, California Earthquake · 27 km SSW of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 47 km ESE of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 30 km NW of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 48 km NNW of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 36 km NNE 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 33.8508, -117.8703. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 21 km (13 mi) | SSE | earthquakes near Orange County |
| Los Angeles County, CA | 53 km (33 mi) | NW | earthquakes near Los Angeles County |
| Ventura County, CA | 129 km (80 mi) | WNW | earthquakes near Ventura County |
| San Diego County, CA | 137 km (85 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
48 earthquakes have been recorded within 50 km since this one.
- 1.6 8km ESE of Yorba Linda, CA
- 1.5 5km ENE of Rancho Cucamonga, CA
- 3.1 5km WNW of Willowbrook, CA
- 2.1 5km WNW of Willowbrook, CA
- 1.6 4km N of Gardena, CA
- 1.7 12km SSE of San Pedro, CA
- 1.6 11km S of San Pedro, CA
- 1.8 3km WSW of East Los Angeles, CA
- 1.7 5km NE of Yorba Linda, CA
- 1.9 5km SSE of Home Gardens, CA
- 2.4 4km SSW of Yorba Linda, CA
- 1.6 7km WSW of Huntington Beach, CA
- 2.1 4km SSW of Yorba Linda, CA
- 1.6 4km ESE of Placentia, CA
- 1.6 4km SSW of Yorba Linda, 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.