Wellington, Dec 18
Seismologists in New Zealand and Australia are expecting a significant damage from the large earthquake that struck Vanuatu on Tuesday.
The 7.3-magnitude shallow earthquake caused strong shaking near the capital Port Vila, about 30 km from the epicentre, at 12:47 local time, with a depth of 43 km, the US Geological Survey said. The earthquake, described by locals as a "violent, high-frequency vertical shake," left at least 14 people dead and hundreds more injured so far, and an initial tsunami warning has since been lifted.
Associate Professor Kasper van Wijk at the Department of Physics, University of Auckland, said this particular earthquake was shallow and close to Port Vila, so significant damage would be expected, as Vanuatu is situated, like New Zealand, on top of a subduction zone. Mark Stirling, chair of Earthquake Science at the University of Otago, noted that this earthquake occurred at ground zero of one of the most active plate boundaries. The subduction zone between the Vanuatu microplate and Australian plate was moving extremely fast, about 170 mm per year, making major earthquakes commonplace in the region.
Associate Professor Fabio Capitanio from the School of Earth Atmosphere and Environment at Monash University mentioned that the recurrence time of these earthquakes was estimated to be around every 100 years, although this cannot be used as a future projection. Behzad Fatahi of Civil and Earthquake Engineering at the University of Technology Sydney emphasized that Vanuatu, a Pacific island nation of over 80 islands and a population of approximately 320,000, sits in the highly seismically active "Ring of Fire." Port Vila is the closest major urban area to the epicentre and is likely to experience the strongest impacts.
Aftershocks can be serious and sometimes nearly as dangerous as the main event, Fatahi said, calling on residents in Port Vila, as well as nearby regions like New Caledonia, Fiji, and the Solomon Islands, to remain alert for further shaking, according to Xinhua news agency. In 2009, two powerful earthquakes with magnitudes larger than 7.7 struck this region within 15 minutes of each other. In 2021, the Loyalty Islands earthquake triggered multiple smaller earthquakes and tsunamis.
Fatahi also warned of secondary hazards such as soil liquefaction and landslides, particularly in coastal cliffs and hilly areas west of Port Vila, where ground instability could worsen with aftershocks. Tuesday's quake caused severe damage to local buildings, including those housing the New Zealand High Commission as well as the United States, French, and British embassies. Prime Minister Christopher Luxon stated that New Zealand was ready to help if needed. There has been significant damage across Vanuatu, according to the Red Cross.