Magnitude 6.9 quake strikes off Vanuatu coast; tsunami warning issued, then withdrawn

A preliminary magnitude 6.9 earthquake struck off the coast of Vanuatu in the South Pacific on Friday, October 23, according to the United States Geological Survey (USGS), prompting a tsunami warning for the surrounding area. The warning was later withdrawn.

The quake struck at around 1.30 p.m. and was centred about 197 kilometres (122 miles) west-north-west of Port Olry, at a depth of roughly 10 kilometres, the USGS said. Earthquakes at such shallow depths are more likely to be felt at the surface and have a greater potential to disturb the seafloor than deeper ones, although the size of any tsunami depends on how the fault moved and how much water was displaced.

Several aftershocks were recorded in the area, including a preliminary magnitude 6.3 tremor, the agency said. There were no immediate reports of damage or casualties.

Vanuatu is an archipelago of roughly 80 islands home to about 300,000 people, lying along the Pacific "Ring of Fire" — a belt of intense seismic and volcanic activity that encircles much of the Pacific basin. Strong earthquakes are a regular occurrence in the region, and authorities routinely issue and then lift tsunami advisories as data from monitoring stations is reviewed.

Tsunami warnings for the South Pacific are typically issued by regional monitoring centres in coordination with national agencies such as the Vanuatu Meteorology and Geo-hazards Department. Such alerts are initially based on preliminary estimates of magnitude, location and depth, and are updated or cancelled as sea-level gauges and deep-ocean sensors confirm whether a wave has actually been generated.

The initial magnitude and depth readings issued in the first minutes after a quake are also subject to revision as seismologists analyse more data.

The region has experienced destructive earthquakes in the past. In December 2024, a magnitude 7.3 earthquake struck near the capital, Port Vila, causing damage to buildings and loss of life. Friday's tremor was centred well away from the capital and at a comparable shallow depth.

The USGS said it had received no immediate indications of ground shaking strong enough to cause widespread damage, and there were no early reports of injury. Officials in Vanuatu had not issued a detailed statement on the event at the time of reporting.

Residents in coastal areas of the affected islands are advised to follow guidance from national disaster management authorities, who issue the official all-clear once the tsunami threat has passed. Boats and coastal communities are generally asked to remain alert until such confirmation is issued, as the withdrawal of a warning does not always mean sea conditions have fully returned to normal.

This report is based on preliminary data from seismological agencies and will be updated if revised figures or damage assessments become available.