Earthquake · reviewed by a seismologist
M 1.5ml
Earthquake near Brea, CA
No earthquake was likely felt in Brea in the 24 hours to 7:16 am PST (15:16 UTC). The last one was M 3.2, 30 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 Brea
This page: a magnitude 1.5 earthquake was recorded 4 km (2 mi) east-northeast of Brea, CA, at 12:12 pm PST on 28 December 2019 (20:12 UTC), 5.8 km deep.
USGS: 4km ENE of Brea, CA
5 km (3 mi) N of Placentia, CA · 51 km (32 mi) E of Los Angeles, CA
- When
- 12:12 pm PST on 28 December 2019 ()
- Where
- 4 km (2 mi) east-northeast of Brea, CA · earthquakes near Brea
- Magnitude
- M 1.5 (ml)
- Depth
- 5.8 km below the surface
- Felt
- no reports yet
- Nearest
- Orange County, 29 km SSE
- Nearest mapped fault
- Puente Hills blind thrust system, 3 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 2505 days ago
Earthquake alerts for Brea, 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 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 8 km (5 mi) from the epicentre. In Brea, 4 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: Brea 4 km, intensity II · Placentia 6 km, intensity II · Rowland Heights 6 km, intensity II · Yorba Linda 7 km, intensity II · La Habra 8 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
- Around the size people start to feel M 3.0 170× the energy of this one
- This earthquake M 1.5 about 5.6 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 20,000 times the energy of this one.
Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:
- 6.4 The 1933 Long Beach, California Earthquake · 35 km SSW of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 50 km ESE of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 25 km NW of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 40 km NNW of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 28 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 33.9295, -117.8645. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 29 km (18 mi) | SSE | earthquakes near Orange County |
| Los Angeles County, CA | 47 km (29 mi) | NW | earthquakes near Los Angeles County |
| Ventura County, CA | 126 km (78 mi) | WNW | earthquakes near Ventura County |
| San Diego County, CA | 143 km (89 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
54 earthquakes have been recorded within 50 km since this one.
- 1.6 0km S of View Park-Windsor Hills, CA
- 1.6 8km SSE of Home Gardens, CA
- 1.6 0km S of View Park-Windsor Hills, CA
- 1.6 1km SE of View Park-Windsor Hills, CA
- 1.6 0km SE of View Park-Windsor Hills, CA
- 3.7 1km S of View Park-Windsor Hills, CA
- 2.1 1km S of View Park-Windsor Hills, CA
- 1.6 2km NNE of Laguna Niguel, CA
- 1.7 4km E of Rancho Cucamonga, CA
- 1.9 3km NNW of Walnut, CA
- 1.7 5km SSE of Home Gardens, CA
- 1.5 2km SSE of View Park-Windsor Hills, CA
- 1.6 8km WNW of Lytle Creek, CA
- 1.6 3km SSW of Willowbrook, CA
- 1.6 7km NW of Glen Avon, 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.