M3.9 earthquake 83 km W of Illapel, Chile
A magnitude 3.9 earthquake struck 83 km W of Illapel, Chile on Sat, Oct 16, 2021, 5:14 PM GMT-3 (20:14 UTC), 16 km (10 mi) below the surface.
A larger quake followed: M4.4 49 km SW of Illapel, Chile. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 3.9 (Mwr, regional moment), minor
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2021-10-16 20:14:46 UTC
- Depth
- 16.0 km (9.9 mi), shallow
- Epicenter
- 31.674° S, 72.053° W
- Region
- Chile
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
No one has reported feeling this quake to the USGS.
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Faulting
- Reverse (thrust)
- Moment magnitude
- 3.9 Mwr
- Nodal plane 1
- Strike 5°, dip 32°, rake 102°
- Nodal plane 2
- Strike 170°, dip 58°, rake 82°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 4.6 km horizontally, 6.0 km in depth
- Magnitude uncertainty
- ±0.06
- Depth from
- From location
- Station coverage gap
- 182°, poorly surrounded by stations
- Stations used
- 44
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 4 in the 60 days after this one and 5 in the 30 days before it.
After
- 4.280 km W of Illapel, Chile · 1812 days ago · 20 km deep · 4 km away · felt by 5
- 4.080 km WNW of Illapel, Chile · 1798 days ago · 12 km deep · 40 km away · felt by 4
- 4.449 km SW of Illapel, Chile · 1775 days ago · 44 km deep · 56 km away · felt by 1
- 4.065 km W of La Ligua, Chile · 1772 days ago · 21 km deep · 79 km away · felt by 2
Before
- 4.483 km W of Illapel, Chile · 1814 days ago · 10 km deep · 4 km away · felt by 1
- 4.178 km W of Illapel, Chile · 1815 days ago · 18 km deep · 5 km away
- 4.389 km W of Illapel, Chile · 1816 days ago · 10 km deep · 6 km away · felt by 2
- 4.089 km W of Illapel, Chile · 1826 days ago · 18 km deep · 6 km away
- 4.689 km W of Illapel, Chile · 1826 days ago · 17 km deep · 6 km away · felt by 8
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000fv9z. Read Sun, Oct 4, 2026, 10:46 PM UTC.