Vanuatu Earthquake: Tsunami Warning Lifted After Twin Quakes

Two powerful earthquakes struck the sea off Vanuatu on Saturday, triggering a tsunami warning for the South Pacific island nation before monitors declared the threat over within the hour. The larger tremor, revised to magnitude 6.9, hit at 1:31 p.m. local time, followed about four minutes later by a magnitude 6.3 quake nearby. No casualties or damage were immediately reported, and coastal residents who had been told to move to higher ground were later told the danger had passed.

KEY TAKEAWAYS: Two earthquakes struck off Vanuatu on Saturday, October 24 — a magnitude 6.9 tremor at 1:31 p.m. local time and a magnitude 6.3 quake about four minutes later. The Pacific Tsunami Warning Center warned of possible dangerous waves within 300 kilometres of the epicentre, then declared the threat over less than an hour later. No casualties or damage were immediately reported.

Flat illustration of a Pacific island coastline with concentric seismic wave rings spreading across a deep navy sea and a yellow warning triangle above the water — Illustration: WHAT TODAY?

Two tremors, minutes apart

The first and larger earthquake struck at 02:31 GMT on Saturday, October 24 — 1:31 p.m. in Vanuatu — with its epicentre about 197 kilometres west-northwest of Port-Olry, a town on Espiritu Santo, the country’s second-largest island. The United States Geological Survey (USGS) put the quake at a depth of about 10 kilometres below the seabed. A second tremor, magnitude 6.3, followed at 02:35 GMT, roughly four minutes later, with its epicentre about 170 kilometres northwest of Port-Olry at a similar depth. The USGS assigned the second quake a green alert level, its lowest, indicating a low likelihood of significant casualties or damage.

Both tremors were offshore, in the waters northwest of Espiritu Santo and the Banks Islands, where Sola is the main town. Their distance from land — nearly 200 kilometres — is one reason the shaking caused no immediate reports of destruction, despite the size of the quakes. Shallow earthquakes of this magnitude can still be dangerous, however, because they displace large volumes of seawater, which is why the tsunami warning followed so quickly.

Why two different magnitudes were reported

Readers following the story on Saturday may have seen the main tremor described as both magnitude 7.2 and magnitude 6.9. Both figures refer to the same earthquake. The USGS first measured it automatically at 7.2, then revised the estimate down to 6.9 as seismologists reviewed the data — a routine refinement that happens with large offshore quakes, when early readings come from automated systems before analysts verify them.

The genuinely separate second earthquake was the magnitude 6.3 tremor four minutes later. Some early reports confused the revised 6.9 figure with a second event; in fact, the sequence was one large quake, revised downward, followed by a distinct smaller one. Vanuatu’s own geo-hazards monitors put the second shock slightly higher, at 6.5 — another reminder that early magnitude figures from different agencies can differ by a few tenths while the data is still being processed.

The warning — and the all-clear

The Pacific Tsunami Warning Center in Hawaii issued an initial advisory warning that dangerous tsunami waves could strike coasts within 300 kilometres of the epicentre. It estimated the first wave could reach Espiritu Santo at about 3:01 a.m. UTC, while cautioning that arrival times could vary and that the first wave might not be the largest. Vanuatu’s Geological Hazards Department issued its own warning, urging people in coastal areas to evacuate to higher ground while the alert was active.

Less than an hour after the mainshock, at 03:28 GMT, the Pacific Tsunami Warning Center announced that the tsunami threat had passed. It said minor sea-level fluctuations could continue along some nearby coastlines for several hours, but that no further action was needed beyond normal caution near the sea. Vanuatu’s authorities subsequently lifted their warning. Former prime minister Alatoi Ishmael Kalsakau wrote on social media that aftershocks were continuing — he counted five quakes on Saturday — and urged residents to stay safe and keep checking official apps for updates.

Why Vanuatu shakes so often

Earthquakes are a fact of life in Vanuatu. The archipelago of about 80 islands sits on the Pacific Ring of Fire, the arc of intense seismic and volcanic activity that runs around the rim of the Pacific Ocean, where tectonic plates grind against each other. Vanuatu lies near the boundary where the Australian plate slides beneath the Pacific plate, a collision zone that produces frequent tremors, some of them very large.

That geography makes the country’s warning systems unusually important. With many communities living close to the shoreline on low-lying islands, the time between a quake and a possible wave can be short, and the official advice — move inland and uphill immediately when a strong quake is felt or a warning is issued — is drilled into residents. Saturday’s sequence showed the system working as designed: a warning issued within minutes, coastal areas alerted, and an all-clear once monitoring showed the sea had settled.

The same forces that shook Vanuatu this weekend have been active across the region in recent days. A magnitude 7.0 earthquake struck Tibet on Friday, killing 16 people and destroying 339 homes, a reminder that the same tectonic pressures run through Asia and the Pacific. Vanuatu’s outcome on Saturday — a major offshore quake with no reported casualties — owed much to the quakes’ distance from shore and to a warning chain that moved fast.

What happens next

Aftershocks are expected to continue in the area, and Vanuatu’s geo-hazards department will keep monitoring sea levels and seismic activity in the coming days. Residents have been advised to stay alert, follow official updates and exercise normal caution near the coast. Authorities will also assess whether any remote coastal communities experienced damage that has not yet been reported, given the distance of the epicentre from the main population centres.

For now, the story of Saturday’s quakes is one of a warning system doing its job: two strong tremors, a rapid alert, an orderly move to higher ground, and an all-clear within the hour. This article will be updated if Vanuatu’s authorities report any damage or further significant aftershocks.

Frequently asked questions

Where did the Vanuatu earthquakes happen?

The earthquakes struck offshore, northwest of Espiritu Santo, Vanuatu’s second-largest island. The larger quake’s epicentre was about 197 kilometres west-northwest of Port-Olry, and the second quake struck about 170 kilometres northwest of the town, both at a depth of around 10 kilometres.

Was there a tsunami?

No destructive tsunami was reported. The Pacific Tsunami Warning Center warned that dangerous waves were possible within 300 kilometres of the epicentre, but in a bulletin issued less than an hour after the mainshock it declared the threat had passed, noting only minor sea-level fluctuations might continue for a few hours.

Why was the magnitude first reported as 7.2 and then 6.9?

The USGS initially measured the quake automatically at magnitude 7.2, then revised it to 6.9 after seismologists reviewed the data. This is a routine refinement for large offshore earthquakes. The 7.2 and 6.9 figures describe the same quake; the separate second tremor measured 6.3.

Was anyone hurt or was anything damaged?

No casualties or damage were immediately reported after the earthquakes, according to monitoring agencies and early official accounts. Authorities were still checking remote coastal communities, and the USGS gave the second quake its lowest alert level for likely casualties and damage.

Why does Vanuatu get so many earthquakes?

Vanuatu sits on the Pacific Ring of Fire, near the boundary where the Australian tectonic plate slides beneath the Pacific plate. This collision zone produces frequent earthquakes and volcanic activity, which is why the island nation has a dedicated geo-hazards department and a well-practised tsunami warning system.