A swarm of strong aftershocks rattled waters off northern Vanuatu on Saturday, 24 October 2026, hours after the region’s magnitude 6.9 earthquake. The Vanuatu aftershocks included at least 10 events of magnitude 5.0 or greater between 02:31 and 05:23 UTC, according to USGS listings reported by The Watchers.
The sequence included a magnitude 6.3 earthquake as well as shocks of magnitude 5.1, 5.2, 5.7, 5.8, 5.3, 5.0, 5.1 and 5.8 in the hours after the main event. Officials said the epicentres were concentrated offshore northwest of the country’s northern islands.
Offshore epicentres limit damage risk
According to USGS data, a magnitude 5.9 earthquake was recorded at 08:56 UTC, about 196 kilometres northwest of Port-Olry, also at 10 kilometres depth. A magnitude 5.8 event at 04:12 UTC was about 203 kilometres northwest of Port-Olry, officials said.
The Global Disaster Alert and Coordination System assigned green alerts to the magnitude 6.9 and 6.3 events, indicating low expected humanitarian impact in its rapid assessments. It estimated about 40,000 people were exposed to intensity IV shaking from the first event.
That offshore distance is a key reason no major damage was immediately reported, seismologists said. Shaking on land was felt at lower intensity than it would have been if the same quakes had struck directly beneath a town.
Monitoring continues for further shocks
Vanuatu lies along an active convergent plate boundary in the southwest Pacific, where subduction generates frequent earthquakes, according to The Watchers. The 24 October sequence was concentrated offshore northwest of the northern islands.
Officials said aftershocks can continue for days after a large shallow earthquake and may occasionally approach the size of the main shock. Residents were advised to stay alert for official updates and to avoid damaged buildings until they are checked.
Maritime operators in the region were also watching for any disruption, officials said, although the offshore location and green alerts pointed to limited impact on ports and shipping lanes.
Seismologists said the sequence would be studied to understand how stress transferred along the plate boundary after the main shock, and they urged coastal residents to keep emergency kits ready, know evacuation routes, and to report any damage to local authorities so a full picture of the offshore sequence could be built.
