Magnitude7.0

Reviewed by USGSPeru44y ago

M7.0 earthquake 92 km NNE of La Peca, Peru

Tuesday, April 12, 1983, 12:07:54 UTC · 4.843°S, 78.103°W

A magnitude 7.0 earthquake struck 92 km NNE of La Peca, Peru on Tuesday, April 12, 1983, 12:07:54 UTC, at a depth of 104.2 km (intermediate). It is the strongest earthquake within 300 km since an M7.4 on July 27, 1971.

Magnitude
7.0
Major · mw
Depth
104 km
Intermediate
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: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

477 kilotons of TNT

That is about 32 times the Hiroshima bomb. It released about 1,000 times the energy of a magnitude 5.0.

Tectonic setting

225 km

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

Depth: intermediate

104 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 200 km

USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M4.8 on April 15, 1983. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.0
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.816 km NE of Yantzaza, Ecuador44y ago · 141 km NW of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 100 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 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 67 recorded deaths. The most severe:

  1. 1928M7.3

    Chacahpoyas,Huancabamba,Cajamarca,Pinpincos

    14 May 1928 · 91 km away · intensity X

    29 deathsSevere damage ($5–24M)

  2. 1968M6.8

    San Martin,Moyobamba,Yantalo,Rioja,Lamas

    19 Jun 1968 · 141 km away

    15 deathsUnder $1 million damage

  3. 1972M6.1

    Juanjui

    20 Mar 1972 · 261 km away · intensity IX

    12 deaths$20 million damage

  4. 1983M6.5

    Chimbote

    12 Apr 1983 · 0 km away

    10 deathsUnder $1 million damage

  5. 1971M6.3

    Guayaquil

    27 Jul 1971 · 251 km away · intensity VII

    1 deathModerate damage ($1–5M)

  6. 1913M7.7

    Gonzanama, San Pedro, Molleture

    24 Feb 1913 · 231 km away · intensity VII

    Severe damage ($5–24M)

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

Nearby trackers

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