Magnitude7.8

Reviewed by USGSPapua New Guinea108y ago

M7.8 earthquake 74 km SSW of Kokopo, Papua New Guinea

Monday, February 2, 1920, 11:22:24 UTC · 4.967°S, 152.017°E

A magnitude 7.8 earthquake struck 74 km SSW of Kokopo, Papua New Guinea on Monday, February 2, 1920, 11:22:24 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M8.2 on May 6, 1919.

Magnitude
7.8
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

7.8 megatons of TNT

That is about 520 times the Hiroshima bomb. It released about 16,406 times the energy of a magnitude 5.0.

Tectonic setting

91 km

from the nearest mapped plate boundary, between the South Bismarck and Solomon Sea plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

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 19 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 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1 recorded deaths. The most severe:

  1. 1878

    Bismarck Sea

    4 Feb 1878 · 84 km away

    1 deathtsunami

  2. 1899

    New Ireland: East Coast

    15 Jan 1899 · 219 km away

    Moderate damage ($1–5M)tsunami

  3. 1919M8.2

    Solomon Islands

    6 May 1919 · 205 km away

    Limited damage (under $1M)tsunami

  4. 1916M7.9

    Solomon Islands

    1 Jan 1916 · 64 km away

    Limited damage (under $1M)tsunami

  5. 1920M7.7

    New Britain

    2 Feb 1920 · 281 km away

    Limited damage (under $1M)tsunami

  6. 1900M6.8

    Bismarck Sea

    10 Sep 1900 · 108 km away

    Limited damage (under $1M)tsunami

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

Nearby trackers

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