Magnitude8.1

Reviewed by USGSPeru85y ago

M8.1 earthquake 21 km NNE of Minas de Marcona, Peru

Monday, August 24, 1942, 22:50:31 UTC · 15.041°S, 75.025°W

A magnitude 8.1 earthquake struck 21 km NNE of Minas de Marcona, Peru on Monday, August 24, 1942, 22:50:31 UTC, at a depth of 30.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude
8.1
Great · mw
Depth
30 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

28 km

from the nearest mapped plate boundary, between the Altiplano and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

30 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 3 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M6.3 on August 25, 1942. 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. 5.948 km SSW of San Juan, Peru85y ago · 87 km S of this epicenter
  2. 6.064 km W of San Juan, Peru85y ago · 91 km SW of this epicenter
  3. 6.360 km W of San Juan, Peru85y ago · 79 km W of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 16 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 17 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 408 recorded deaths. The most severe:

  1. 1821

    Camana, Ocona, Caraveli

    10 Jul 1821 · 250 km away · intensity VIII

    162 deathsSevere damage ($5–24M)

  2. 1913M6.3

    Amyaraes, Abancay, Casaya, Soraya

    4 Nov 1913 · 247 km away · intensity X

    150 deathsSevere damage ($5–24M)

  3. 1914

    Pararca,Paysa,Colta,Oyala

    2 Dec 1914 · 197 km away · intensity X

    34 deathsSevere damage ($5–24M)

  4. 1813

    Ica

    30 Mar 1813 · 112 km away · intensity VII

    32 deathsModerate damage ($1–5M)

  5. 1942M8.2

    Ica, Nazca

    24 Aug 1942 · 105 km away · intensity IX

    30 deathsSevere damage ($5–24M)tsunami

  6. 1913M7.9

    Caraveli, Chuquibamba, Ocona, Atico

    6 Aug 1913 · 244 km away · intensity X

    Severe damage ($5–24M)tsunami

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

Nearby trackers

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