Magnitude7.5

Reviewed by USGSNew Caledonia7y ago

M7.5 earthquake 166 km ESE of Tadine, New Caledonia

Wednesday, December 5, 2018, 04:18:08 UTC · 21.950°S, 169.427°E

A magnitude 7.5 earthquake struck 166 km ESE of Tadine, New Caledonia on Wednesday, December 5, 2018, 04:18:08 UTC, at a depth of 10.0 km (shallow). USGS received 17 “Did You Feel It?” reports, with a maximum reported intensity of III (weak). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M7.5 on January 4, 1998.

Tsunami flagUSGS sets this flag for large events in oceanic regions so tsunami warning centers review them. It does not by itself mean a tsunami occurred. Check tsunami.gov and local authorities for official messages.

Magnitude
7.5
Major · mww
Depth
10 km
Shallow
Felt reports
17
Max intensity III
Est. shaking
VI
Strong (ShakeMap)
PAGER alert
Green
Impact estimate
Tsunami
Flag
Check tsunami.gov

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

2.7 megatons of TNT

That is about 178 times the Hiroshima bomb. It released about 5,623 times the energy of a magnitude 5.0.

Tectonic setting

3 km

from the nearest mapped plate boundary, between the New Hebrides and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

10 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

Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.

PlaceIntensityReportsDistance
Nouméa, Sud, New CaledoniaIII · Weak12309 km
Mont-Doré, Sud, New CaledoniaIII · Weak1295 km
Yaté, Sud, New CaledoniaIII · Weak1260 km
Brisbane, Queensland, AustraliaII · Weak11767 km
Vila, Shefa, VanuatuII · Weak1481 km
Houaïlu, Nord, New CaledoniaII · Weak1400 km
I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

Modelled from the ShakeMap and population data. Alert level green: low likelihood of casualties and damage.

VI · Strong shaking
1,300 people
V · Moderate shaking
15,000 people
IV · Light shaking
251,000 people
III · Weak shaking
99,000 people

Estimated shaking in nearby towns

  • TadinePopulation 7,500V · Moderate
  • WecapitalPopulation 10,000V · Moderate
  • VaoPopulation 1,900IV · Light
  • PaitaPopulation 13,000IV · Light
  • BouloupariPopulation 2,100IV · Light
  • IsangelcapitalPopulation 1,400IV · Light
  • La FoacapitalPopulation 2,900IV · Light
  • KonecapitalPopulation 4,600IV · Light

After the main event

Aftershocks within 200 km

USGS lists 187 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.6 on December 5, 2018. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,478 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 28 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 26 recorded deaths. The most severe:

  1. 1875M8.1

    Loyalty Islands: Lifou Island

    28 Mar 1875 · 237 km away

    26 deathsSevere damage ($5–24M)tsunami

  2. 1901M7.9

    Loyalty Islands

    9 Aug 1901 · 59 km away

    Moderate damage ($1–5M)tsunami

  3. 1920M8.1

    Loyalty Islands

    20 Sep 1920 · 240 km away

    Limited damage (under $1M)tsunami

  4. 2018M7.5

    Loyalty Islands

    5 Dec 2018 · 0 km away · intensity III

    Limited damage (under $1M)tsunami

  5. 2010M7.3

    Vanuatu Islands

    25 Dec 2010 · 293 km away

    Limited damage (under $1M)tsunami

  6. 1913M8.1

    Vanuatu Islands

    14 Oct 1913 · 276 km away

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

Nearby trackers

Closest city pages