A phreatic eruption occurred on December 9 around 14:11 local time on White Island in northern New Zealand. This short-lived impulsive event affected the bottom of the crater. Activity seems to have decreased since the eruption.
Monitoring data shows that there was a short-lived eruption that generated an ash plume at about 3,600 meters above the vent. Ashes covered the floor of the main crater, where there were about fifty people. We regret the death of one person, and many others burned. The balance sheet could get heavier in the next few hours as people go missing.
Seven helicopters joined the island just after the eruption to bring relief and evacuate the wounded to the nearest hospitals.
The fall of the ashes seems to be limited to the island and we do not expect a smaller amount of ash to reach the Eastern Cape in the next hours.
Monitoring equipment is still functioning and a steady decline in activity has been observed since the eruption. There is still a great deal of uncertainty about future changes, but currently there is no sign of escalation.
After a temporary elevation at 14:30 local at alert level 4 and orange code, the GeoNet lowered the alert level to 3 to 16:25 local.
Aerial view of White Island after the eruption - New Zealand Herald photo via AP / George Novak 09.12.2019
Professor Shane Cronin, Volcanologist, University of Auckland, comments:
"Sudden and unplanned eruptions of volcanoes such as White Island can be expected at any time. Magma is close to the surface, and heat and resulting gases heat surface and groundwater to form strong hydrothermal systems. We know that hydrothermal and phreatic eruptions can occur suddenly and with little or no warning because they are caused by the expansion of superheated water into steam.
The expected dangers of such events are the violent ejection of hot blocks and ashes, and the formation of currents "similar to hurricanes of wet ashes and coarse particles that radiate from the blast mouth. These can be fatal in terms of impact trauma, burns and breathing problems. Eruptions are short-lived, but once they occur, there is a good chance that others will occur, usually smaller, as the system rebalances. "
The NZ Herald in its edition of 19:02 this December 9 mentions five people dead and the police expect that the death toll will increase. Twenty-three people were transported from the island, all with some degree of burns. A number of them were taken to hospitals in Whakatane and Middlemore.
There are still a number of people on the island who are missing. New Zealanders and overseas tourists, including some of the Ovation of the Seas cruise ship that was visiting Tauranga. would be involved. The cruise ship will not leave the port before the return of the missing passengers.
A damaged and ash-covered helicopter near the crater was also seen near the edge of the island.
The deputy commissioner of the national operation commander said he was not sure if he could pick up those who had not been found yet. "At this point, it is too dangerous for the police and rescue to reach the island ... the island is currently covered with ash and volcanic materials."
Sources: GeoNet - NZ Radio - National Police - On-site observers, including Michael Schade and Zurraspismo - local media including NZ Herald
White island west rim 09.12.2019 14h30-14h40 NZDT - photos Inst. og geological and nuclear sciences ltd - one click to enlarge