Small steam explosions on Whakaari / White Island, alert level remains the same

A series of “small steam explosions” were detected yesterday at Whakaari / White Island.

The GNS science agency detected the low-energy blasts using air pressure seismic and acoustic sensors on the island.

They occurred at 3 p.m. Tuesday and were short-lived, about 30 minutes, the agency said.

At least 20 individual pulses were produced, which may have produced “minor traces” of ash near the vent for a few minutes.

MetService satellite images did not detect ash in the atmosphere, he said.

Meanwhile, the island’s webcam images suggested that more vigorous steam pulses could have come from the active vent of the volcano at the time, GNS said.

Since then, activity has returned to a low level, he said. The island’s volcanic alert level remains at 1 and the aviation color code will remain “green.”

“While Volcanic Alert Level 1 is primarily associated with environmental hazards, eruptions can still occur with little or no warning.”

The lowest alert level is 0, classified as “no volcanic disturbances”. Level 1 means “minor volcanic disturbances”.

The main hazards of alert level 1 include the discharge of hot volcanic steam and gases, earthquakes, landslides and hydrothermal activity.

GNS volcanology team leader Nico Fournier said explosions like these have not been common since the December 9 eruption last year.

“But we have seen them many times in the past at the volcano. For example, during 2012/13.

“These small steam bursts can be difficult to detect on webcams and we can only detect them thanks to our seismic and acoustic monitoring sensors on the island.”

Whakaari / White Island erupted on December 9 of last year at 2.11 pm, claiming the lives of 22 tourists and tour guides.

There were 47 people on the island when it exploded. Many survivors were seriously injured.