7.5 Earthquake 168km ESE of Tadine New Caledonia – On Wednesday, December 5, 2018, around at 15:18 local time, an earthquake (see video below) measured at a magnitude 7.5 struck just east of New Caledonia at a pretty shallow depth of 10 kilometres (6.2 miles).
New Caledonia is a special collectivity of France in the southwest Pacific Ocean, 1,210 km (750 mi) east of Australia and 20,000 km (12,000 mi) from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Chesterfield Islands, the Belep archipelago, the Isle of Pines, and a few remote islets.
The National Weather Service issued a tsunami warning shortly afterwards for a thousands of kilometres of coastlines. Noting that “tsunami waves have been observed”, they forecasted hazardous waves for some coasts, including New Caledonia and Vanuatu.
The eastern margin of the Australia plate is one of the most sesimically active areas of the world due to high rates of convergence between the Australia and Pacific plates. In the region of New Zealand, the 3000 km long Australia-Pacific plate boundary extends from south of Macquarie Island to the southern Kermadec Island chain. It includes an oceanic transform (the Macquarie Ridge), two oppositely verging subduction zones (Puysegur and Hikurangi), and a transpressive continental transform, the Alpine Fault through South Island, New Zealand.
Since 1900 there have been 15 M7.5+ earthquakes recorded near New Zealand. Nine of these, and the four largest, occurred along or near the Macquarie Ridge, including the 1989 M8.2 event on the ridge itself, and the 2004 M8.1 event 200 km to the west of the plate boundary, reflecting intraplate deformation. The largest recorded earthquake in New Zealand itself was the 1931 M7.8 Hawke’s Bay earthquake, which killed 256 people. The last M7.5+ earthquake along the Alpine Fault was 170 years ago; studies of the faults’ strain accumulation suggest that similar events are likely to occur again.
- Tadine, Loyalty Islands, New Caledonia 168.2 km (104.5 mi) WNW – Population: 7,492
- Wé, Loyalty Islands, New Caledonia 254.4 km (158.1 mi) WNW – Population: 10,375
- Mont-Dore, South Province, New Caledonia 298.9 km (185.8 mi) W – Population: 24,680
- Dumbéa, South Province, New Caledonia 309.9 km (192.6 mi) W – Population: 19,346
- Nouméa, South Province, New Caledonia 311.1 km (193.3 mi) W – Population: 93,060
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- 8.2 Earthquake 280 Kilometers NNE Ndoi Island Fiji
- Mount Rinjani Volcano 6.5 Earthquake Mudslides 15 Dead 150 Injured
- Hawaii Volcano Triggers Island 6.9 Earthquake
Video:Magnitude 7.5 Earthquake – (New Caledonia) Loyalty Islands – Dec. 5, 2018