M6.1 earthquake 11 km N of Ilabaya, Peru
A magnitude 6.1 earthquake struck 11 km N of Ilabaya, Peru on Sun, Feb 26, 1984, 3:18 AM GMT-5 (08:18 UTC), 113 km (70 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.1 (Mw, moment), strong
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1984-02-26 08:18:19 UTC
- Depth
- 113.1 km (70.3 mi), intermediate-depth
- Epicenter
- 17.316° S, 70.526° W
- Region
- Peru
- Strongest shaking
- IV, light 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 |
|---|---|---|---|
| 6.1 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 6.09 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 6.1 | Mwc, centroid moment | Global CMT project | Preliminary |
What happened
The USGS’s account of the effects of this earthquake.
Felt (V) at Arequipa, Peru and Arica, Chile. FAULT PLANE SOLUTION: P-Waves NP1:Strike=328 Dip=82 Slip=-90 NP2:Strike=148 Dip=8 Slip=-90 Principal Axes: (T) Plg=37 Azm=58 (P) Plg=53 Azm=238 Comment: The focal mechanism is poorly controlled and corresponds to normal faulting. The preferred fault plane is NP1. MOMENT TENSOR SOLUTION Dep 108 No. of sta: 14 Moment Tensor; Scale 10**25 d-cm Mrr=-0.66 Mtt=1.17 Mff=-0.51 Mrt=0.58 Mrf=-1.49 Mtf=-0.85 Principal axes: (T) Val=2.06 Plg=26 Azm=33 (N) Val=0.02 Plg=34 Azm=142 (P) Val=-2.08 Plg=45 Azm=275 Best Double Couple:Mo=2.1*10**25 NP1:Strike=76 Dip=36 Slip=-161 NP2:Strike=330 Dip=79 Slip=-55 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 19S, 46C Centroid Location: Origin Time 08:18:24.7 0.2 Lat 17.31S 0.02 Lon 70.65W 0.03 Dep 115.6 1.8 Half-duration 4.1 Moment Tensor; Scale 10**25 D-CM Mrr=-0.85 0.04 Mtt=-0.11 0.05 Mff=0.96 0.05 Mrt=0.70 0.03 Mrf=-1.07 0.03 Mtf=-0.63 0.05 Principal Axes: (T) Val=1.85 Plg=25 Azm=63 (N) Val=-0.38 Plg=7 Azm=330 (P) Val=-1.47 Plg=64 Azm=225 Best Double Couple:Mo=1.7*10**25 NP1:Strike=169 Dip=21 Slip=-69 NP2:Strike=327 Dip=71 Slip=-98
From the USGS event page for usp0002291. 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
- IV, light shaking
- Peak ground acceleration
- 4.1% of gravity
- Peak ground velocity
- 0.4 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
- CONSTRAINED_BY_DEPTH_PHASES
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 3.1 and up: 2 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayPeru earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0002291 (also filed as gcmtb022684a, gcmt19840226081816, iscgem559885). Read Fri, Oct 2, 2026, 5:46 PM UTC.