PNG volcano: Tsunami warning for communities living near erupting Kadovar Island

© Provided by ABC News Hundreds of villagers have evacuated from Kadovar Island, paddling to a nearby island.

Authorities in Papua New Guinea have warned people living near the Kadovar Island volcano to prepare for the worst, with fears an eruption there could trigger a tsunami.

The long-dormant volcano rumbled to life late last week, sending ash into the sky and forcing around 700 people to evacuate to a neighbouring island.

The entire landmass of Kadovar Island is essentially just the 365-metre-tall volcano, sitting off PNG's north coast.

Video taken during an aerial assessment of the island on Saturday showed a spectacular plume of smoke and ash billowing from its dome.

Ricky Wobar, the District Administrator for Wewak — the largest town on the mainland — was in the plane.

"The volcano was blowing out ashes, very thick ashes … It started on Friday around 11 o'clock," he said.

Mr Wobar said the nearly 700 people who live on the island took it upon themselves to evacuate, paddling to nearby Blup Blup island.

"The volcano smoke was very thick, and ashes were thrown out from the volcano. There was no actual lava but only thick ashes and smoke."

"If there wasn't any initiative by boat, there would have been a very serious disaster," he said.

"They were also using small canoes, paddling across to Blup Blup. There was a banana boat but no engine."

© Facebook: Samaritan Aviation Kadovar Island consists almost entirely of the volcano, which was thought to be dormant.

Last eruption thought to be 300 years ago

There are no recorded instances of the Kadovar Island volcano erupting in the recent past — however historical records suggest it could be one of two "burning islands" mentioned by the 17th century British explorer Willliam Dampier.

There was an increase in thermal activity at the site in the late 1970s, and an increase in the frequency of earthquakes in mid-2015, however both eventually died away.

It was not listed as one of Papua New Guinea's 16 volcanoes deemed to be active, and was not routinely monitored.

Steve Saunders, a Principal Geophysics Surveyor and Acting Director at the Rabaul Volcano Observatory, said the volcano was considered "potentially active" before last week's events.

Mr Saunders said because of the lack of equipment, it was hard to predict what would happen next.

"Two things may happen. The rise of magma may stall and it will just stop and then hopefully the magma will cool down and things will go back to normal," he said.

"Or the magma will continue cracking to the surface … and because of the amount of time since the last eruption, the magma is likely gas-rich and then the eruption will be quite violent."

For the moment scientists can only monitor the volcano from satellites or aerial flyovers, but Mr Saunders said authorities are trying to get the appropriate equipment to the island.

"We are sourcing funding, the government organisations are trying to raise money here and we do have overseas donors who may help if we need to ask."

Tsunami possible as volcano erupts

Matthew Moihoi, a seismologist at PNG's Geophysical Observatory in Port Moresby, said any more serious activity could generate a tsunami.

"The base is somewhere underneath the ocean floor, and if there's a chance the eruption might escalate then there might be a potential of a caldera collapse," he said.

"And if that is the case then it will definitely generate a tsunami and then it will affect a wider community."

Steve Saunders from the Rabaul Volcano Observatory agrees.

"The magnitude of the tsunami would depend on how much material is moving into the water," he said.

"So it could just be small landslides causing a ripple that you may see on the coast, or if a large chunk of the volcano falls off there would be a larger tsunami."

Through provincial governments in PNG, Mr Saunders said the observatory is advising people to prepare for the possibility of a tsunami.

"We've basically got to prepare for the worst-case scenario, we can't just say we hope it will just be small," he said.

"We are just saying just prepare yourselves for the possibility of tsunami, and of course that's a very difficult thing to say because we try not to panic people, but we want people to be ready in case there are some."

Provincial authorities are working to provide assistance to those displaced and are meeting to discuss what more will be needed in coming days and weeks.

"We have deployed three dinghies with police personnel, they are right now on the island and are assessing the situation, and making sure all the people have been evacuated," Mr Wobar said.

"We will definitely provide relief supplies, like foodstuffs, medical supplies, shelter, water containers and other necessary relief supplies."