Magnitude6.6

Reviewed by USGSPeru39y ago

M6.6 earthquake 36 km SSW of Locumba, Peru

Thursday, August 13, 1987, 15:23:06 UTC · 17.897°S, 70.931°W

A magnitude 6.6 earthquake struck 36 km SSW of Locumba, Peru on Thursday, August 13, 1987, 15:23:06 UTC, at a depth of 36.5 km (shallow). It is the strongest earthquake within 300 km since an M7.2 on August 8, 1987.

Magnitude
6.6
Strong · 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

120 kilotons of TNT

That is about 8 times the Hiroshima bomb. It released about 251 times the energy of a magnitude 5.0.

Tectonic setting

167 km

from the nearest mapped plate boundary, between the Nazca and Altiplano 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 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 182 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 48 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 26,299 recorded deaths. The most severe:

  1. 1868M8.5

    Arica

    13 Aug 1868 · 79 km away · intensity XI

    25,000 deaths$300 million damagetsunami

  2. 1833M7.7

    Peru: Tacna; Chile: Arica

    18 Sep 1833 · 40 km away · intensity VIII

    700 deathsSevere damage ($5–24M)tsunami

  3. 1784M8.0

    Arequipa,Camana,Moquegua,Tambo

    13 May 1784 · 192 km away · intensity X

    383 deathsSevere damage ($5–24M)tsunami

  4. 1821

    Camana, Ocona, Caraveli

    10 Jul 1821 · 294 km away · intensity VIII

    162 deathsSevere damage ($5–24M)

  5. 1958M7.0

    Arequipa

    15 Jan 1958 · 230 km away · intensity IX

    28 deathsSevere damage ($5–24M)

  6. 1979M6.9

    Arequipa

    16 Feb 1979 · 248 km away

    18 deathsModerate damage ($1–5M)

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

Nearby trackers

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