Taranaki civil defense authorities have begun training an army of 500 volunteers for when, not if, Mt Taranaki erupts, and for major weather events.
Whether it erupted was a matter of when, not if, according to the Taranaki Civil Defense Emergency Management (CDEM). Scientists are seeing an increase in the likelihood of an eruption over the next 50 years, Civil Defense group manager Craig Campbell-Smart said.
“Technically it’s termed a quiescent stage – it’s not dormant but not actively erupting.” In its new five year plan, it singles out preparing for an eruption as a priority. One hundred people have already been trained; most of them people from the region’s councils, and more were being recruited from the public.
“There’s a very broad selection of skills we require,” he said. Roles included leadership, planning and intelligence, operations, field staff, logistics, public information management and welfare. The system was based on those used by the military.
“It’s very disciplined, about building our capability so we can stand up at very short notice.” CDEM was also decentralizing and setting up operations centers to deal with emergencies on a district council level. Campbell-Smart said it was difficult to predict exactly what would happen in an eruption as it depended on the size and type of the event.
“Worst case scenario we’re looking at very strong gas eruption that would produce a super heated gas cloud with debris in it – that’s the stuff that’s an immediate threat to life, that’s about 800 degrees Celsius and that would roll down the mountainside. That’s the least likely scenario but it’s a potential.”
An eruption of gas and ash was the most likely event, and there would be advance warning through increased localized seismic activity in the area. “It could go quite high and fall on other areas, which is why it’s a national hazard,” he said.
In Taranaki, ash would fall into rivers and over towns, depending on the wind. It was very abrasive and would accumulate on roads and paddocks, and contaminate stock feed and water supplies. It would also affect air conditioning systems, municipal water supplies and cause telecommunications equipment to overheat and fail.
Rain would make it worse.
“If ash gets wet it doubles in weight. It could collapse roofs, and accumulate on the flanks of mountain in river systems, resulting in lahars.” The next eruption could take one of three possible general forms, Taranaki CDEM said.
– Small explosive pumice eruption.
– Lava dome eruption.
– Large explosive pumice eruption. The last one occurred in AD1655 – although this would not be likely.
A small explosive pumice eruption could signal a period of more frequent eruptions, while a lava-dome eruption could continue for many years or decades, the CDEM website said.
The last major eruption occurred about 1854. Despite the risk of an eruption, the current alert level set by GeoNet – which monitors the volcano – is at zero, with no volcanic activity. However, it notes: “An eruption may occur at any [alert] level, and levels may not move in sequence as activity can change rapidly.”
A volcanic event on Mt Taranaki is “almost certain” and the consequences would be “catastrophic”, experts say. An eruption of the volcano could have serious physical effects on the landscape, affect the region’s economy and threaten ecosystems. A Taranaki CDEM map showing evacuation zones revealed the areas in the region most at risk.
The red zone held the most risk – and those who remained there were “unlikely to survive”. At the other end of the spectrum, the green zone was considered sheltered from volcanic activity except for ash fall. You can keep an eye on Taranaki via a webcam here.