QuakeScout
Magnitude6.3

Reviewed by USGSChile87y ago

M6.3 earthquake 67 km NW of Iquique, Chile

Sunday, October 6, 1940, 15:38:24 UTC · 19.760°S, 70.586°W

A magnitude 6.3 earthquake struck 67 km NW of Iquique, Chile on Sunday, October 6, 1940, 15:38:24 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.2 on October 4, 1940.

Magnitude
6.3
Strong · mw
Depth
15 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
V
Moderate (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

40 kilotons of TNT

That is about 3 times the Hiroshima bomb. It released about 83 times the energy of a magnitude 5.0.

Tectonic setting

93 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

15 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 16 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 7.3136 km WSW of Challapata, BoliviaJune 6, 1915 · 276 km E of this epicenter
  2. 7.334 km S of Iquique, ChileFebruary 23, 1933 · 94 km SE of this epicenter
  3. 7.2Near the coast of Tarapaca, ChileOctober 4, 1940 · 30 km SE of this epicenter
  4. 6.9119 km W of Iquique, ChileSeptember 15, 1911 · 87 km SW of this epicenter
  5. 6.925 km ENE of Arica, ChileAugust 30, 1906 · 164 km N of this epicenter
  6. 6.9181 km W of Iquique, ChileAugust 25, 1916 · 143 km W of this epicenter
  7. 6.987 km NNW of Iquique, ChileDecember 26, 1906 · 23 km N of this epicenter
  8. 6.6152 km WNW of Tocopilla, ChileOctober 22, 1920 · 229 km SW of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 36 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 28,085 recorded deaths. The most severe:

  1. 1868M8.5

    Arica

    13 Aug 1868 · 136 km away · intensity XI

    25,000 deaths$300 million damagetsunami

  2. 1877M8.3

    Off North Coast

    10 May 1877 · 194 km away · intensity XI

    2,385 deaths$2 million damagetsunami

  3. 1833M7.7

    Peru: Tacna; Chile: Arica

    18 Sep 1833 · 174 km away · intensity VIII

    700 deathsSevere damage ($5–24M)tsunami

  4. 1878M7.9

    Tarapaca

    23 Jan 1878 · 32 km away · intensity VIII

    Severe damage ($5–24M)tsunami

  5. 1871M7.3

    Chile

    5 Oct 1871 · 63 km away · intensity X

    Severe damage ($5–24M)tsunami

  6. 1934M6.9

    Iquique, Pisagua, Sapiga, Negrero

    4 Dec 1934 · 117 km away

    Moderate damage ($1–5M)tsunami

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

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