Fascinated by a force of nature

IT WAS on a field trip to California that Natalia Deligne first fell in love with volcanoes. At just 20 years old she was struck by how beautiful a lava flow was.

‘‘Then the more I learned about it, the more I was impressed with how destructive volcanoes are and how much they give to us.’’

They not only create a lot of real estate around the world, they are also useful at providing plenty of free fertiliser in the form of ash and minerals.

It’s this fascination that has seen Deligne undertake study and research at various universities and volcanic hot spots, and she’s currently a volcanic hazard and risk modeller at GNS Science in Lower Hutt.

While many volcanologists study what’s happening underneath the ground, she is all about when the hot stuff hits the surface.

Deligne is one of a team that looks at what could happen when volcanoes erupt and how to deal with the fallout, literally, of ash, magma and gases.

Sometimes the impact of an eruption has the potential for a huge disruption, requiring some large-scale planning.

For instance Mt Taranaki, which last burped around 1854 but had a major cough in 1655 with a lot of ash going over the central North Island, is surrounded by 500,000 dairy cows. Should the seismographs indicate a possible volcanic eruption, the call has to be made whether to take action that could involve moving that very large herd out of harm’s way. Making the call would be a local government decision, but it will be done on the information provided by the GNS volcanology team of 18.

Deligne divides her time between Avalon and Wairakei near Taupo, which is the sharp end for the monitoring regime that’s in place in New Zealand. When she’s not watching what’s going on with the volcanoes, she’s researching ways to reduce the effects of the inevitable eruptions.

‘‘Most of the volcanology department is focused on what happens underground and what leads to eruptions.

‘‘I look at what happens once an eruption’s underway – where do the hazards go, what do those hazards mean for people and infrastructure and things like that.’’

These hazards can be ash clouds affecting water supplies, lahars going down rivers and possibly what molten rock could do to a high-end suburb in Auckland.

She does a lot of work with researchers at the University of Canterbury to model the effects of things such as ash, and what different levels of ash falls could do to a region.

‘‘We look at things like what the different consequences are of 3mm of ash, or a metre of ash and what that means for buildings, the power network, transportation or how quickly people could drink water again.’’

Plus she supervises two volcanology students at the University of Canterbury. ‘‘They’re an enthusiastic bunch.’’ There is also an Auckland study group that aims to ensure the region has the information it needs to deal with volcanic events there.

Auckland is unusual in New Zealand being built over the top of an active volcanic field, which will erupt again, with potentially dire consequences.

‘‘In Auckland, we suspect the pyroclastic surge will be a real nightmare.’’

This will be a mix of superheated gas and ash which can travel at hundreds of kilometres an hour, making it impossible to escape from.

‘‘Think of a really hot avalanche,’’ she says.

Luckily most New Zealand volcanoes have parks around them, she says. Whether this is due to good luck or smart planning, it is a useful way to limit the direct effects on the population.

Funnily enough, history shows similar patterns of settlement.

‘‘If you look at a lot of indigenous cultures around the world they have stories about volcanoes that essentially provide planning tips – some areas will be taboo and we notice that the areas that are taboo are around volcanic vents, for example.’’

Deligne was born in Belgium to a Belgian mathematician father and a Russian mother. They emigrated to the US and Deligne grew up in New Jersey and went to university at the California Institute of Technology, did her masters at the University of Bristol in England and her PhD at the University of Oregon.

Her interest in science stems from having a generally curious nature, whether it be history, geology or astronomy.

In fact, astronomy was her first choice for a degree but the physics involved wasn’t to her taste so she moved to geology.

Much like history, she says geology has many tales to tell.

‘‘There’s a story everywhere you go,’’ she says. ‘‘And the way the Earth influences us is fascinating.’’

Her particular interest in volcanology was fed by her studies at the University of Bristol, one of the leading centres for volcanology.

While Britain doesn’t have any volcanoes right next door, there is no shortage of them just up the road in Iceland, and in Montserrat in the Caribbean, which is a British territory. (For quiz night questions, the Soufrie` re Hills volcano is probably a good answer for: ‘‘Name the only active British volcano’’.)

After her PhD in 2012 she applied for a job at GNS. There are only so many specialist volcanology jobs going at any time and she was thrilled to get this one, which is a mix of hard science and useful planning to offset the downside effects of major eruptions.

She works with a number of organisations and councils to reduce these threats.

She says some places are better placed to withstand volcanic outputs than others. For instance, a town with an enclosed water treatment plant can supply water to residents but one that is open to the air could be crippled with a decent ash fall.

Sometimes little things can make a big difference.

‘‘With air conditioning units, whether the air intake is pointing up or down can have consequences on how much ash your building can handle.’’

So there is a lot of liaison with power companies and water supply operators to think about what to do to strengthen the infrastructure.

‘‘Just being able to reduce the consequences is rewarding.

‘‘There will be challenges, we can’t prevent the ash from falling, but we can put systems in place to reduce the challenges.’’

Deligne’s other role is being a duty officer for GNS, monitoring activity and assessing the Volcano Alert Level (VAL) of New Zealand volcanoes, ranging from VAL 0, such as Taranaki or the Auckland volcanic field, to the more common VAL 1 on Ruapehu and White Island, which usually bubble away year round or VAL 3 to 5 for erupting volcanoes.

At the time of the interview Ruapehu was at VAL 2, due to the increased gas flux and heightened seismicity and temperature in the crater lake but that since has gone back down. The lake temperature heating and cooling cycle happens a lot there.

Every few weeks she goes to Wairakei, near Taupo, where most of GNS’s volcanologists are based, to be the volcanologist on call for GeoNet. Those weeks she keeps an eye on all the monitoring data from around New Zealand. She spends a week there and when back in Wellington she provides support to the volcano monitoring team.

This year, apart from Ruapehu, there was a small eruption on White Island in April that got the seismographs jumping. Information on events goes first to the MetService and to the Civil Aviation Authority so planes can avoid ash clouds, the Department of Conservation, Civil Defence and other affected groups.

‘‘Within half an hour of an event we will send out an alert bulletin.’’

Outside of New Zealand GNS works with the Ministry of Foreign Affairs and Trade on a monitoring programme for Vanuatu and in 2015 it set up monitoring gear after an eruption in Tonga.

‘‘We’re always available to provide assistance.’’

Outside of working hours Deligne is a keen singer. She started in a choir when she was 10 and is currently a soprano in Wellington’s Orpheus Choir. She’s also been a gymnast, having recently taken it up again after moving to New Zealand and competing at the Masters Games in February.

But she’s chuffed to be in an organisation doing what’s she’s trained to do.

‘‘And I get to learn all sorts of things from really intelligent people,’’

For more information go to: geonet.org.nz/volcano