The Rabaul Volcanological Observatory in Papua New Guinea says the eruption of Kadovar Island remains dynamic.
The tiny island off the north coast of PNG's mainland erupted earlier this month. About 700 residents were promptly evacuated from the island whose vegetation has been covered in ash.
The Observatory's acting assistant director Steve Saunders said a seismometre has been placed on the island.
"Visually in the last few days it's been stable. It's still ashing and steaming, and there's a slow lava flow oozing out on one side. But the seismometres have confirmed that there are still what we call high frequency earthquakes occurring which means there is rock-breaking occurring, so the situation is still dynamic."
According to Mr Saunders, Kadovar was still releasing significant amounts of sulfur dioxide, which indicated the presence of fresh magma.
He said latest data to hand showed six high-frequency earthquakes measured in about twelve to eighteen hours, indicating kadovar was "still responding to some sort of stress".
"So it is still possible that fresh magma will rise to the surface," he explained. "But at the moment it's still 50/50."
Meanwhile, Mr Saunders refuted claims that nearby Biem island is erupting in conjunction with Kadovar. He said that recorded dates of volcanic eruptions in the Bismarck Sea show there was no correlation between them.
Nonetheless, the East Sepik provincial government has ordered the evacuation of the whole Schouten Island group, amid reports circulating in the provincial capital Wewak that Biem had also burst into volcanic activity in recent days.
But Mr Saunders said there had been no unusual volcanic activity on Biem.
"Nor at any other volcano in the Bismarck Sea. Everything else is doing what it normally does, and there is no linkage between these volcanoes. So if one erupts, it will not make another one erupt," he explained.
"If there was a correlation you would have an eruption and it would be the same date on other volcanoes. But they're not. They're all unrelated."