Scientists have revealed the cause of a strange night glow and large volcanic plumes which have been seen at Whakaari/White Island recently.
People who were watching Geonet's cameras over the past few weeks have reported a strange glow and large plumes of steam. Now Geonet has revealed what is causing them. The plumes are due to "ideal weather conditions", according to Geonet.
"The steam and gas plume originates from several active vents on the island and are clustered in and around the craters formed in December 2019.
"Several factors contribute to how the steam and gas plumes appear above the volcano. These include heat flow, gas output, and the presence of groundwater, lakelets or crater lakes. Humidity, dew point, air temperature and wind speed can also play a role.
"Line all of these up like we did over the last couple of weeks and you can have large spectacular steam and gas plumes over the volcano," it said in a statement on its website.
Geonet also revealed what was causing the strange glow that could be seen on the crater rim camera at night. It said the glow is actually hot steam and gas which appears to 'glow' when it's dark.
"Since June 30 we have seen a night glow return to the island, visible from our crater rim camera at night. Our Volcanic cameras have both daylight and low light cameras installed, allowing pictures to be taken at night when there is enough ambient light (such as from a full moon).
"The low light cameras are also able to see the hot steam and gas vents, and these appear as a 'glow' on our cameras on the island. This usually requires moderate-strong and hot emissions from the vents on the volcano for this to occur.
"Observations from a flight on July 15 confirmed temperatures of 500-600 °C are now present."
Whakaari/White Island erupted at 2:11pm on December 9, 2019, killing 22 people and injuring dozens. Two local tour guides were among the dead, with the body of Hayden Marshall-Inman washed out to sea.
Public tours to the island were stopped after the tragedy.
