Earthquake · reviewed by a seismologist
M 2.3ml
Earthquake near Fullerton, CA
No earthquake was likely felt in Fullerton in the 24 hours to 5:03 am PST (13:03 UTC). The last one was M 3.2, 26 km (16 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 Fullerton
This page: a magnitude 2.3 earthquake was recorded in Fullerton, CA, at 8:28 pm PST on 4 December 2023 (04:28 UTC), 5.5 km deep. 121 people have reported feeling it to USGS.
USGS: 2 km E of Fullerton, CA
in Fullerton, CA · 49 km (31 mi) ESE of Los Angeles, CA
- When
- 8:28 pm PST on 4 December 2023 ()
- Where
- in Fullerton, CA · earthquakes near Fullerton
- Magnitude
- M 2.3 (ml)
- Depth
- 5.5 km below the surface
- Felt
- 121 reports · strongest reported intensity V
- Nearest
- Orange County, 25 km SSE
- Nearest mapped fault
- Puente Hills blind thrust system, under 1 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 1071 days ago
Earthquake alerts for Fullerton, CA
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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 20 km (12 mi) from the epicentre. 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: Fullerton in town, intensity III · Placentia 3 km, intensity III · Brea 5 km, intensity III · Anaheim 5 km, intensity III · La Habra 7 km, intensity II · Buena Park 9 km, intensity II · Yorba Linda 9 km, intensity II · La Mirada 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 98 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 150,000× the energy of this one
- Magna, Utah 2020 M 5.7 110,000× the energy of this one
- Around the size people start to feel M 3.0 9.8× the energy of this one
- This earthquake M 2.3 about 98 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 2,000 times the energy of this one.
Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:
- 6.4 The 1933 Long Beach, California Earthquake · 29 km SSW of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 26 km NW of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 45 km N of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 35 km NNE of this epicentre
- 5.4 5km S of Chino Hills, CA · 15 km ENE 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 33.8763, -117.9053. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 25 km (16 mi) | SSE | earthquakes near Orange County |
| Los Angeles County, CA | 48 km (30 mi) | NW | earthquakes near Los Angeles County |
| Ventura County, CA | 125 km (78 mi) | WNW | earthquakes near Ventura County |
| San Diego County, CA | 141 km (88 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
45 earthquakes have been recorded within 50 km since this one.
- 1.6 5 km SSE of Home Gardens, CA
- 1.6 3 km ENE of View Park-Windsor Hills, CA
- 1.9 4 km ESE of Placentia, CA
- 1.6 2 km NE of Yorba Linda, CA
- 2.0 3 km SE of Ontario, CA
- 1.5 9 km N of Rancho Cucamonga, CA
- 1.9 10 km ENE of Villa Park, CA
- 1.7 4 km SE of Home Gardens, CA
- 1.9 2 km ENE of El Segundo, CA
- 2.2 2 km N of Huntington Park, CA
- 2.5 3 km N of Huntington Park, CA
- 1.7 4 km N of Laguna Beach, CA
- 2.0 3 km SE of Marina del Rey, CA
- 3.6 3 km ESE of Ontario, CA
- 1.8 6 km 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.