M3.9 earthquake 94 km S of Pacocha, Peru
A magnitude 3.9 earthquake struck 94 km S of Pacocha, Peru on Tue, Oct 9, 2018, 6:08 AM GMT-5 (11:08 UTC), 35 km (22 mi) below the surface.
A larger quake followed: M4.4 21 km NW of Arica, 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
- 2018-10-09 11:08:57 UTC
- Depth
- 35.2 km (21.9 mi), shallow
- Epicenter
- 18.494° S, 71.232° W
- Region
- Peru
- 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
- Oblique reverse
- Moment magnitude
- 3.9 Mwr
- Nodal plane 1
- Strike 169°, dip 69°, rake 130°
- Nodal plane 2
- Strike 282°, dip 45°, rake 31°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 5.4 km horizontally, 12.1 km in depth
- Magnitude uncertainty
- ±0.08
- Depth from
- From location
- Station coverage gap
- 208°, poorly surrounded by stations
- Stations used
- 28
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 2 in the 60 days after this one and 1 in the 30 days before it.
After
- 4.421 km NW of Arica, Chile · 2905 days ago · 66 km deep · 83 km away · felt by 1
- 4.035 km WSW of Arica, Chile · 2885 days ago · 45 km deep · 65 km away
Before
Earthquakes todayPeru earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us1000h9ak. Read Fri, Oct 2, 2026, 2:42 AM UTC.