What happened on Whakaari?
THE ERUPTION BEGAN at 9.35pm with big heaves inside the crater. By 10.03pm it was pelting the nearby walking track with projectiles, but withheld its final energy until 10.11pm, when with a whoomph it sent a plume sky-high. A scalding current of steam and debris, coloured green by hydrothermally altered rock, rolled right across the track at 11m/s, and down to the south-eastern bays.
This eruption took place on Whakaari/White Island, New Zealand, on 27 April 2016, more than three years before the catastrophe in December last year that claimed the lives of 21 people (17 of them Australians) and injured 26 others.
Geologists from GNS Science, NZ’s leading provider of geoscientific research, reconstructed the pulses of the eruption from acoustic and seismic data, and, three weeks later when they could safely land on the island again, began figuring out the reach of those pulses. The resulting scientific paper was published on 1 April last year, and its authors warned: “These eruptions clearly pose a significant hazard to the tourists that visit the island.” More than a quarter of the walking track had been bombarded by rock fragments. The pyroclastic surge, though just 5mm thick at its extremities, had nonetheless covered 95 per cent of the track.
YOU MIGHT WONDER if this eruption triggered any changes, but it happened at night, with no witnesses, so it simply passed on by. You might, therefore, be tempted to wish it into the daylight, when tourists would have been afoot, because then it might have garnered more notice – since it came in pulses of ascending violence, there would have been time to run, and the headlines would have been nothing more than “Tour operators reassess risk after near miss”. It would have been a wake-up call that produced only meetings over cups of tea, with scribbled notes, bottom-line business interests weighed against risk, and some kind of agreed reform.
Three years later, at 2.11pm on 9 December 2019, there was another eruption – one that came without warning. Except, perhaps, that on 8 December the instruments that measure tremors in nanometres, a White Island Tours vessel, and he videoed much of the island tour. At about 1.30pm, he panned along the hot, strangely bright stream flowing from the crater lake. Amid the snap and spit of boiling mineral water, the microphone caught an off-camera aside by a White Island Tours guide: “I’m a little bit worried why it’s going green.”
