M3.9 earthquake 86 km WSW of Copiapó, Chile
A magnitude 3.9 earthquake struck 86 km WSW of Copiapó, Chile on Fri, Oct 15, 2021, 7:57 AM GMT-3 (10:57 UTC), 28 km (18 mi) below the surface.
A larger quake followed: M4.8 89 km NNW of Vallenar, 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
- 2021-10-15 10:57:37 UTC
- Depth
- 28.5 km (17.7 mi), shallow
- Epicenter
- 27.798° S, 71.057° 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 183°, dip 59°, rake 71°
- Nodal plane 2
- Strike 36°, dip 36°, rake 118°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 4.2 km horizontally, 5.1 km in depth
- Magnitude uncertainty
- ±0.09
- Depth from
- From location
- Station coverage gap
- 139°
- Stations used
- 34
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 3 in the 30 days before it.
After
- 4.292 km WSW of Copiapó, Chile · 1811 days ago · 20 km deep · 20 km away · felt by 1
- 4.562 km W of Vallenar, Chile · 1794 days ago · 42 km deep · 97 km away · felt by 1
- 4.889 km NNW of Vallenar, Chile · 1771 days ago · 33 km deep · 5 km away · felt by 6
Before
Earthquakes todayChile earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000fuum. Read Sun, Oct 4, 2026, 9:14 AM UTC.