GeoNet confirmed the volcano had erupted for about 10 minutes.
It started about 10.20am, with the volcano producing a steam column which rose about two kilometres above the island, GNS vulcanologist Steve Sherburn said.
“Whether it’s going to develop into something over the next few hours or couple of days is too soon to tell,” he said.
“There’s always steam coming out of the island but there was a big shot of steam for about 10 minutes – now the island is looking like it did before the eruption.”
It was too early to liken the recent eruption with its past behaviour, but Sherburn said it was “vaguely similar” to an eruption in early August last year.
The alert level went from one up to two, signalling minor eruptive activity, and the aviation colour code went from green to red.
Sherburn said the island was “pretty calm” at the moment.
The plume was clearly visible from Whakatane, and as far as suburban Tauranga and Mt Maunganui this morning.
Western Bay of Plenty locals told Stuff they had immediately recognised the steam rising above the landscape as evidence of a White Island eruption.
A retiree who’d lived along the coast all her life said it was by far the largest White Island plume she’d ever seen.
“It’s a constant threat along this coast. She could go at any time.”
Sharni McKay, of Frontier Helicopters in Whakatane, said: “I was just looking out and there was a big plume of gas coming out the top.
“I could definitely see the cloud coming out.”
The plume was mainly white and looked much like a cloud.
White Island Tours marketing manager Patrick O’Sullivan said the large steam plume could be seen over the island about 10.20am.
The plume was quite white and had been blown away within a matter of minutes.
“Normally you can see a fair bit of steam coming out of the island. How you could tell it was a little bit out of the normal today, the steam plume was a lot higher than usual.”
A boatload of tourists had been heading for the island but had not reached it and would now not be landing today.
White Island started to show signs of new activity last month, including jets of gas being shot through its small lake and sediments being ejected 30 metres into the air.
“The potential for larger, more explosive eruptions that might impact on visitors to the island is always present. Any larger eruptions may occur with no warning to any visitors to the island,” GNS Science said at the time.
RAYC is hosting the Round White Island Race on the 22nd November!