Magnitude8.1

Reviewed by USGSPeru60y ago

M8.1 earthquake 67 km W of Paramonga, Peru

Monday, October 17, 1966, 21:41:58 UTC · 10.704°S, 78.448°W

A magnitude 8.1 earthquake struck 67 km W of Paramonga, Peru on Monday, October 17, 1966, 21:41:58 UTC, at a depth of 37.4 km (shallow). It is the strongest earthquake within 300 km since an M8.2 on May 24, 1940.

Magnitude
8.1
Great · mw
Depth
37 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
VII
Very strong (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

21 megatons of TNT

That is about 1,415 times the Hiroshima bomb. It released about 44,668 times the energy of a magnitude 5.0.

Tectonic setting

141 km

from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

37 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

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 400 km

USGS lists 1 M2.5+ earthquake within 400 km in the following 30 days; the largest was M5.7 on October 29, 1966. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M7M81h6h1d3d7d14d30dMainshock M8.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.7118 km SW of Huarmey, Peru60y ago · 58 km W of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 17 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 8,585 recorded deaths. The most severe:

  1. 1746M8.0

    Lima, Callao

    29 Oct 1746 · 198 km away · intensity XI

    5,941 deathsExtreme damage ($25M+)tsunami

  2. 1725M7.7

    Trujillo, Ancash, Lima

    7 Jan 1725 · 199 km away · intensity IX

    1,500 deathsSevere damage ($5–24M)

  3. 1946M7.3

    Jocaibamba,Cerro Angaschaj,Cerro Sillapata

    10 Nov 1946 · 266 km away · intensity XI

    800 deathsSevere damage ($5–24M)

  4. 1940M8.2

    Peru

    24 May 1940 · 160 km away · intensity X

    179 deathsSevere damage ($5–24M)tsunami

  5. 1966M8.1

    Lima,Huacho,Huaura, Chancay,Supe,San Nicolas

    17 Oct 1966 · 21 km away · intensity IX

    110 deaths$35 million damagetsunami

  6. 1828M8.3

    Lima, Callao

    30 Mar 1828 · 173 km away · intensity VII

    30 deathsModerate damage ($1–5M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

Closest city pages