M6.6 earthquake 36 km SSW of Locumba, Peru
A magnitude 6.6 earthquake struck 36 km SSW of Locumba, Peru on Thu, Aug 13, 1987, 10:23 AM GMT-5 (15:23 UTC), 37 km (23 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.6 (Mw, moment), strong
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1987-08-13 15:23:06 UTC
- Depth
- 36.5 km (22.7 mi), shallow
- Epicenter
- 17.897° S, 70.931° W
- Region
- Peru
- Strongest shaking
- VII, very strong shaking
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 6.6 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 6.49 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 6.5 | Mwc, centroid moment | Global CMT project | Preliminary |
Deaths and damage
From NOAA NCEI’s Significant Earthquake Database (record 5139), matched to this event by time and place.
- Deaths
- 1
- Injuries
- 1
- Damage
- Limited (under about $1 million)
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What happened
The USGS’s account of the effects of this earthquake.
One person killed, one injured and additional damage (V) at Arica, Chile. Felt (IV) at Arequipa and Tacna, Peru. Depth from broadband displacement seismograms. FAULT PLANE SOLUTION: P-Waves NP1:Strike=160 Dip=74 Slip=90 NP2:Strike=340 Dip=16 Slip=90 Principal Axes: (T) Plg=61 Azm=70 (P) Plg=29 Azm=250 Comment: The focal mechanism is poorly controlled and corresponds to reverse faulting. The preferred fault plane is NP2. MOMENT TENSOR SOLUTION Dep 37 No. of sta: 11 Moment Tensor; Scale 10**18 Nm Mrr=5.63 Mtt=-0.23 Mff=-5.40 Mrt=0.84 Mrf=-7.90 Mtf=-1.84 Principal axes: (T) Val=10.00 Plg=61 Azm=72 (N) Val=-0.31 Plg=11 Azm=183 (P) Val=-9.69 Plg=27 Azm=279 Best Double Couple:Mo=9.8*10**18 NP1:Strike=34 Dip=21 Slip=124 NP2:Strike=179 Dip=73 Slip=78 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 27S, 56C M.W.: 15S, 32C Centroid Location: Origin Time 15:23:17.5 0.1 Lat 18.08S 0.02 Lon 71.59W 0.02 Dep 35.9 1.0 Half-duration 3.0 Moment Tensor; Scale 10**18 Nm Mrr=3.76 0.07 Mtt=-0.51 0.04 Mff=-3.26 0.05 Mrt=1.58 0.13 Mrf=-5.15 0.19 Mtf=1.69 0.03 Principal Axes: (T) Val=6.54 Plg=63 Azm=79 (N) Val=0.24 Plg=4 Azm=340 (P) Val=-6.78 Plg=27 Azm=248 Best Double Couple:Mo=6.7*10**18 NP1:Strike=327 Dip=18 Slip=76 NP2:Strike=161 Dip=72 Slip=95
From the USGS event page for usp00037gc. U.S. Geological Survey text and figures are in the public domain.
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- VII, very strong shaking
- Peak ground acceleration
- 23.2% of gravity
- Peak ground velocity
- 2.6 cm/s
- Map
- Automatic
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Depth from
- OPERATOR_ASSIGNED
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 3.6 and up: 0 in the 60 days after this one and 1 in the 30 days before it.
Before
Earthquakes todayPeru earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00037gc (also filed as gcmtc081387b, gcmt19870813152311, atlas19870813152307, iscgem459668). Read Fri, Oct 2, 2026, 2:58 PM UTC.