Earthquake · reviewed by a seismologist
M 4.3mw
Earthquake near Carson, CA
No earthquake was likely felt in Carson in the 24 hours to 2:58 am PST (10:58 UTC). The last one was M 3.2, 10 km (6 mi) ESE, at 12:44 am PDT on 9 October 2026, estimated intensity III (weak) in town; 1,090 felt reports to USGS. Every earthquake near Carson
This page: a magnitude 4.3 earthquake was recorded in Carson, CA, at 7:58 pm PDT on 17 September 2021 (02:58 UTC), 12 km deep. 10,301 people have reported feeling it to USGS.
USGS: 2km E of Carson, CA
25 km (15 mi) SSE of Los Angeles, CA · in Carson, CA
- When
- 7:58 pm PDT on 17 September 2021 ()
- Where
- in Carson, CA · earthquakes near Carson
- Magnitude
- M 4.3 (mw)
- Depth
- 12 km below the surface
- Felt
- 10,301 reports · strongest reported intensity V
- Measured shaking
- intensity VI (ShakeMap)
- USGS impact alert
- green
- Tsunami
- USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
- Nearest
- Los Angeles County, 41 km N
- Nearest mapped fault
- Palos Verdes 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 520 days ago
Earthquake alerts for Carson, CA
Get a notification in this browser when USGS records an earthquake near Carson, CA. No account or email needed.
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 light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.
At this magnitude and depth, people at rest would likely notice it out to about 119 km (74 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: Carson in town, intensity IV · Torrance 7 km, intensity IV · Gardena 8 km, intensity IV · Compton 8 km, intensity IV · Signal Hill 9 km, intensity IV · Willowbrook 10 km, intensity IV · Long Beach 10 km, intensity IV · Lawndale 10 km, intensity IV. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 40 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.3 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 4,300× the energy of this one
- Mineral, Virginia 2011 M 5.8 190× the energy of this one
- Magna, Utah 2020 M 5.7 130× the energy of this one
- This earthquake M 4.3 about 40 tons of TNT
- Around the size people start to feel M 3.0 this one released 83× more
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 2.5 times the energy of this one.
Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 Northridge, California, earthquake · 49 km NNW of this epicentre
- 6.4 The 1933 Long Beach, California Earthquake · 33 km SE of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 31 km NNE of this epicentre
- 5.4 5km S of Chino Hills, CA · 48 km ENE of this epicentre
- 5.3 2 km SSW of Santa Monica, California · 29 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 33.8313, -118.2637. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Los Angeles County, CA | 41 km (25 mi) | N | earthquakes near Los Angeles County |
| Orange County, CA | 48 km (30 mi) | ESE | earthquakes near Orange County |
| Ventura County, CA | 99 km (62 mi) | NW | earthquakes near Ventura 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.
- 2.0 22km SW of Huntington Beach, CA
- 2.3 3km ESE of Carson, CA
- 1.5 2km ESE of Carson, CA
- 2.2 11km S of Malibu Beach, CA
- 1.9 3km ESE of Carson, CA
- 2.5 3km SE of Carson, CA
- 1.5 2km SE of Carson, CA
- 1.8 4km ESE of Carson, CA
- 1.5 0km SE of Carson, CA
- 2.8 3km SSE of Carson, CA
- 1.8 2km WNW of Marina del Rey, CA
- 1.6 2km SE of Carson, CA
- 1.8 19km S of San Pedro, CA
- 1.7 2km ESE of Carson, CA
- 2.5 19km S of San Pedro, 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.