ResearchPublished 22 August 2019
NZ scientist to fly drone over rowdy PNG volcano
A Kiwi scientist is about to get an up-close-and-personal look at one of the world's angriest volcanoes, through a clever approach now also being used here
By Jamie Morton
Originally published on 11 August 2019 in the New Zealand Herald
Rising to 1750m above the Papua New Guinea island of Bougainville – or roughly the same height as Mt Hikurangi on New Zealand's East Coast – Bagana is one of Melanesia's youngest and most active volcanoes.
It's effectively a gigantic symmetrical cone, built up by frequent lava flows, and has been locked in a near-continuous eruptive state for 150 years.
It's also nearly impossible for scientists to reach.
"It's deep in the jungle, it's extremely high and it's extremely active, with frequent eruptions, strong plumes and unstable slopes – there's no way to climb it," Victoria University volcanologist Dr Ian Schipper said.
"But it's also a major gas emitter."
Studies have estimated that Bagana spews several thousand tonnes of sulphur dioxide – the only gas that can be reliably measured from satellite, because of its optical properties - into the atmosphere each day.
"We know that there are a whole lot of other gases coming out of it, like carbon dioxide, hydrogen fluoride and hydrogen chloride, yet we've had no way of measuring it, because there has been no way to do it – until now."
Enter drone technology.
Schipper has been at the forefront of using drones to safely reveal the wealth of information that volcanoes send out in their gas plumes.
In a two-week expedition to Bagana next month, organised by the US-based Deep Carbon Observatory (DCO), he's joining a team of largely UK scientists, led by Manchester University volcanologist Dr Brendan McCormick.
A major focus of the DCO had been to understand more about how carbon dioxide was escaping from volcanoes like Bagana and others worldwide, to create more accurate global estimates of volcanic gas emissions.
"Recently, we had a meeting of a group of volcanologists using drones in Papua New Guinea, and they saw some of my capabilities, so they said, can you come join us at Bagana?" Schipper said.
As it happened, he'd already chosen Bagana as a study subject as part of wider research supported by the Marsden Fund.
"So it's a fabulous opportunity for me."
Elsewhere, Schipper has been pioneering his drone monitoring techniques at Vanuatu's fiery Ambrym volcano – and at White Island in the Bay of Plenty, New Zealand's only regularly de-gassing volcano.
"White Island has a particularly horrible acidic plume, so it's a really good test ground, and pretty accessible."
He was also part of a project in Chile to develop a drone that could handle the heat and acidity in a volcano's plume.
"The first challenge that people think of is temperature, but that's not a big problem, because the plumes cool down very quickly as they leave the vent."
Rather, the main headaches came with the highly reactive gases packed in the plumes – and how they changed air density.
"What we have found is that, if you are trying to hold the drone in the plume region and there's a pulse of new gas that dramatically changes the turbulence and the density of the air around.
"It's really challenging because the drone will drop like a stone, and then you have to fight to recover altitude, so you really have to be on the ball.
"And then there's the chemical reactivity with the bird itself. Even after five minutes flying about in a plume, any exposed metal – which of course includes any electronics – will just decay instantly."
An EQC-funded project he was running at White Island could ultimately offer volcanologists a better idea of how plume chemistry worked – and potentially help give officials more time to act in the event of an impending eruption.
Additional information: Read original article here
Dr Ian Schipper
University of Victoria, Wellington
CONTRACT OR PROJECT ID
VUW1807 'Navigating a Sea of Bias in the Study of Volcanic Gas Emissions: He Waka Eke Noa'