Magnitude7.7

Reviewed by USGSPeru114y ago

M7.7 earthquake 37 km SSW of Atico, Peru

Wednesday, August 6, 1913, 22:14:36 UTC · 16.534°S, 73.738°W

A magnitude 7.7 earthquake struck 37 km SSW of Atico, Peru on Wednesday, August 6, 1913, 22:14:36 UTC, at a depth of 25.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude
7.7
Major · mw
Depth
25 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

5.9 megatons of TNT

That is about 394 times the Hiroshima bomb. It released about 12,445 times the energy of a magnitude 5.0.

Tectonic setting

85 km

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

Depth: shallow

25 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 200 km

USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1 M5.0+ earthquake 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 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 695 recorded deaths. The most severe:

  1. 1784M8.0

    Arequipa,Camana,Moquegua,Tambo

    13 May 1784 · 185 km away · intensity X

    383 deathsSevere damage ($5–24M)tsunami

  2. 1821

    Camana, Ocona, Caraveli

    10 Jul 1821 · 95 km away · intensity VIII

    162 deathsSevere damage ($5–24M)

  3. 1913M6.3

    Amyaraes, Abancay, Casaya, Soraya

    4 Nov 1913 · 275 km away · intensity X

    150 deathsSevere damage ($5–24M)

  4. 1913M7.9

    Caraveli, Chuquibamba, Ocona, Atico

    6 Aug 1913 · 59 km away · intensity X

    Severe damage ($5–24M)tsunami

  5. 1739

    Santa Catalina

    24 Mar 1739 · 277 km away · intensity VII

    Severe damage ($5–24M)

  6. 1725

    Callao

    27 Mar 1725 · 111 km away · intensity VII

    Moderate damage ($1–5M)tsunami

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

Nearby trackers

Closest city pages