Magnitude7.1

Reviewed by USGSVanuatu81y ago

M7.1 earthquake 38 km ESE of Luganville, Vanuatu

Saturday, January 5, 1946, 19:57:26 UTC · 15.691°S, 167.470°E

A magnitude 7.1 earthquake struck 38 km ESE of Luganville, Vanuatu on Saturday, January 5, 1946, 19:57:26 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.1 on January 24, 1927.

Magnitude
7.1
Major · mw
Depth
35 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
VI
Strong (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

607 kilotons of TNT

That is about 40 times the Hiroshima bomb. It released about 1,274 times the energy of a magnitude 5.0.

Tectonic setting

122 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

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 lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M6.3 on January 20, 1946. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.325 km ENE of Norsup, Vanuatu81y ago · 31 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 63 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 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1910M7.2

    Espiritu Santo

    10 Nov 1910 · 215 km away

    Moderate damage ($1–5M)tsunami

  2. 1909

    Espiritu Santo

    8 Jul 1909 · 36 km away

    Moderate damage ($1–5M)tsunami

  3. 1933M6.4

    Malekula

    19 Nov 1933 · 138 km away

    Limited damage (under $1M)tsunami

  4. 1903M7.9

    Vanuatu Islands

    13 May 1903 · 156 km away

  5. 1910M7.9

    Espiritu Santo

    9 Nov 1910 · 161 km away

  6. 1927M7.1

    Port Vila

    24 Jan 1927 · 290 km away

    tsunami

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

Nearby trackers

Closest city pages