Magnitude 7.2 Earthquake Strikes off Vanuatu, Tsunami Warning Issued for Nearby Coasts

A strong earthquake struck the sea off northern Vanuatu early on Saturday, and a tsunami warning was issued for nearby coasts. The United States Geological Survey first measured the quake at magnitude 7.2. It struck at 02:31 UTC, which was 13:31 local time, about 200 kilometres (124 miles) west of Sola, at a depth of 10 kilometres (6.2 miles), Reuters reported. Sola is the capital of Torba Province, the northernmost province of Vanuatu, and sits on the east coast of the island of Vanua Lava.

Tsunami warning, then a lower reviewed reading

The Pacific Tsunami Warning Center said hazardous tsunami waves were possible for coasts located within 300 kilometres of the epicentre, in a warning reported by Livemint. A reviewed calculation from the USGS later put the quake at magnitude 6.9, about 197 kilometres (122 miles) west-northwest of Port-Olry on the island of Espiritu Santo, and the monitoring summary for that reviewed reading listed no tsunami threat. The USGS alert level for the reviewed event was green, which means a low likelihood of casualties and damage. There was no official word from Vanuatu authorities in the first wire reports, and the first reports carried no word of damage or injuries.

More tremors in the same waters

Monitors recorded more tremors in the same area within the hour. A magnitude 6.3 quake struck at 02:35 UTC about 170 kilometres (106 miles) northwest of Port-Olry, and a magnitude 5.2 followed at 03:17 UTC, according to USGS data carried by seismic monitors. Only a handful of felt reports had reached the USGS in the first hours. The epicentre sits far offshore, west of the Banks Islands, in waters dotted with scattered and sparsely populated islands. Luganville, the largest town in the north of the country, is about 247 kilometres southeast of the epicentre.

A restless stretch of the Ring of Fire

Vanuatu sits on the Pacific Ring of Fire, where the Australian Plate and the Pacific Plate meet, and strong quakes are common there. The same waters produced a magnitude 6.3 quake on October 20, which brought no tsunami threat and no reported damage. Seismic monitors counted 25 earthquakes above their reporting threshold within 250 kilometres of Saturday's epicentre in the past 30 days, the largest of them a magnitude 6.9 before Saturday. Saturday's quake was shallow, and shallow quakes are usually felt more strongly than deeper ones of the same size because the energy is released closer to the surface.