Vanuatu has experienced 30 magnitude 7-plus earthquakes in the last 25 years, says regional earthquake and GNS seismologist, Dr. John Ristau.
He said Vanuatu is in a highly seismically active region, like most South Pacific islands, and large quakes were not uncommon.
“The recent earthquake was close to the most populated of Vanuatu’s islands and its capital, Port-Vila,” Ristau said.
“In this region, the Australian tectonic plate is pushing (subducting) beneath the Pacific plate and this earthquake occurred within the Australian plate. Seismologists call this an intraplate earthquake. Intraplate earthquakes often produce strong, high-frequency shaking, which is the type of shaking most damaging to buildings.”
The 7.3 magnitude quake on Tuesday claimed 14 lives, caused injuries to 200 people, and resulted in widespread devastation in the Vanuatu Capital.
“The proximity to Port-Vila and the strong, high-frequency shaking were the main contributing factors to the extensive damage. There have been numerous reports of collapsed buildings and more widespread structural damage. The collapse of buildings in Port-Vila and other population centres could be like what Christchurch experienced in February 2011.”