Magnitude7.5

Reviewed by USGSPapua New Guinea110y ago

M7.5 earthquake 93 km SW of Aitape, Papua New Guinea

Sunday, July 29, 1917, 21:52:31 UTC · 3.705°S, 141.729°E

A magnitude 7.5 earthquake struck 93 km SW of Aitape, Papua New Guinea on Sunday, July 29, 1917, 21:52:31 UTC, at a depth of 35.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude
7.5
Major · mw
Depth
35 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

2.3 megatons of TNT

That is about 150 times the Hiroshima bomb. It released about 4,732 times the energy of a magnitude 5.0.

Tectonic setting

126 km

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

Depth: shallow

35 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 7 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 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5 recorded deaths. The most severe:

  1. 1900M6.9

    Nw. Irian Jaya

    7 Oct 1900 · 195 km away

    5 deathsLimited damage (under $1M)tsunami

  2. 1907M7.4

    Bismarck Sea

    15 Dec 1907 · 109 km away

    Moderate damage ($1–5M)tsunami

  3. 1917M7.5

    Papua New Guinea

    29 Jul 1917 · 0 km away

    tsunami

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

Nearby trackers

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