Reviewed by USGSPeru40y ago
M6.8 earthquake 109 km W of Alianza Cristiana, Peru
Sunday, November 23, 1986, 01:39:23 UTC · 3.342°S, 77.411°W
A magnitude 6.8 earthquake struck 109 km W of Alianza Cristiana, Peru on Sunday, November 23, 1986, 01:39:23 UTC, at a depth of 105.7 km (intermediate). It is the strongest earthquake within 300 km since an M7.0 on April 12, 1983.
- Magnitude
- 6.8
- Strong · mw
- Depth
- 106 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
239 kilotons of TNT
That is about 16 times the Hiroshima bomb. It released about 501 times the energy of a magnitude 5.0.
Tectonic setting
225 km
from the nearest mapped plate boundary, between the North Andes and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
106 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 124 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.516 km W of Barranca, PeruSeptember 28, 1906 · 176 km S of this epicenter
- 7.498 km ESE of Sucúa, EcuadorJuly 27, 1971 · 55 km N of this epicenter
- 7.323 km N of Bellavista, PeruMay 14, 1928 · 272 km SW of this epicenter
- 7.092 km NNE of La Peca, PeruApril 12, 1983 · 184 km SW of this epicenter
- 6.848 km NNE of Segunda Jerusalén - Azunguillo, PeruJune 19, 1968 · 250 km S of this epicenter
- 6.737 km E of Palora, EcuadorMay 17, 1971 · 191 km N of this epicenter
- 6.655 km ENE of Macas, EcuadorMay 10, 1963 · 130 km N of this epicenter
- 6.6122 km SSE of Boca Suno, EcuadorNovember 18, 1982 · 197 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 46,106 recorded deaths. The most severe:
- 1797M8.3
Riobamba, Quito, Cuzco; Peru; Colombia
4 Feb 1797 · 235 km away · intensity XI
40,000 deathsExtreme damage ($25M+)tsunami
- 1949M6.5
Tungurahua
5 Aug 1949 · 254 km away
6,000 deaths$8 million damage
- 1924M6.9
Ecuador
3 Mar 1924 · 234 km away
40 deathsLimited damage (under $1M)
- 1928M7.3
Chacahpoyas,Huancabamba,Cajamarca,Pinpincos
14 May 1928 · 271 km away · intensity X
29 deathsSevere damage ($5–24M)
- 1968M6.8
San Martin,Moyobamba,Yantalo,Rioja,Lamas
19 Jun 1968 · 255 km away
15 deathsUnder $1 million damage
- 1960
Ecuador
30 Jul 1960 · 270 km away
11 deathsLimited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.