QuakeScout
Magnitude4.3

Reviewed by USGSChile40y ago

M4.3 earthquake 85 km ENE of San Pedro de Atacama, Chile

Friday, April 17, 1987, 21:26:20 UTC · 22.754°S, 67.381°W

A magnitude 4.3 earthquake struck 85 km ENE of San Pedro de Atacama, Chile on Friday, April 17, 1987, 21:26:20 UTC, at a depth of 267.9 km (intermediate).

Magnitude
4.3
Light · mb
Depth
268 km
Intermediate
Felt reports
0
Did You Feel It?
Est. shaking
—
No ShakeMap
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquake

In context

How big was it, and why here?

Energy released

43 tons of TNT

That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.

Tectonic setting

139 km

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

Depth: intermediate

268 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 50 km

USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 284 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.2121 km SSE of San Pedro de Atacama, ChileDecember 9, 1950 · 146 km S of this epicenter
  2. 7.751 km W of Atocha, BoliviaNovember 29, 1957 · 212 km N of this epicenter
  3. 7.334 km NE of Tocopilla, ChileDecember 21, 1967 · 282 km W of this epicenter
  4. 7.278 km SW of Colchani, BoliviaOctober 4, 1910 · 225 km N of this epicenter
  5. 7.064 km NNE of Antofagasta, ChileNovember 20, 1928 · 278 km W of this epicenter
  6. 7.052 km W of Abra Pampa, ArgentinaApril 1, 1987 · 121 km E of this epicenter
  7. 6.999 km WNW of San Antonio de los Cobres, ArgentinaFebruary 21, 1971 · 116 km S of this epicenter
  8. 6.881 km WSW of Calama, ChileDecember 23, 1916 · 232 km W of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 7 recorded deaths. The most severe:

  1. 1953M7.4

    Northern

    7 Dec 1953 · 154 km away

    3 deaths$7 million damage

  2. 1967M7.5

    Northern

    21 Dec 1967 · 248 km away

    1 deathModerate damage ($1–5M)tsunami

  3. 1976M7.3

    Pozo Almonte, Oficina Victoria, Arica

    30 Nov 1976 · 295 km away · intensity VIII

    1 deathModerate damage ($1–5M)

  4. 1959M7.5

    Bolivia-Northern Chile

    14 Jun 1959 · 273 km away

    1 deathLimited damage (under $1M)

  5. 1950M8.0

    Chile-Argentina

    9 Dec 1950 · 84 km away · intensity VII

    1 death

  6. 1844M6.5

    Salta, Jujuy, Tucuman

    19 Oct 1844 · 287 km away · intensity VII

    Severe damage ($5–24M)

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

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