Magnitude7.7

Reviewed by USGSVanuatu62y ago

M7.7 earthquake 45 km NNE of Port-Olry, Vanuatu

Thursday, May 20, 1965, 00:40:18 UTC · 14.649°S, 167.200°E

A magnitude 7.7 earthquake struck 45 km NNE of Port-Olry, Vanuatu on Thursday, May 20, 1965, 00:40:18 UTC, at a depth of 50.0 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on December 17, 1957.

Magnitude
7.7
Major · mw
Depth
50 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

5.4 megatons of TNT

That is about 355 times the Hiroshima bomb. It released about 11,220 times the energy of a magnitude 5.0.

Tectonic setting

100 km

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

Depth: shallow

50 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 127 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 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1965M7.6

    Vanuatu Islands

    11 Aug 1965 · 128 km away

    Moderate damage ($1–5M)tsunami

  2. 1910M7.2

    Espiritu Santo

    10 Nov 1910 · 104 km away

    Moderate damage ($1–5M)tsunami

  3. 1909

    Espiritu Santo

    8 Jul 1909 · 95 km away

    Moderate damage ($1–5M)tsunami

  4. 1965M7.4

    Vanuatu Islands

    13 Aug 1965 · 146 km away

    Limited damage (under $1M)tsunami

  5. 1933M6.4

    Malekula

    19 Nov 1933 · 257 km away

    Limited damage (under $1M)tsunami

  6. 1903M7.9

    Vanuatu Islands

    13 May 1903 · 275 km away

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

Nearby trackers

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