New Zealand’s Earthquake Commission (EQC) has teamed up with GNS Science and national weather authority MetService to develop forecasting models for volcanic ashfall to help communities manage future eruptions.

New Zealand is dotted with active volcanoes and ash from an eruption could cause disruption and damage across a large area.

The ground-breaking EQC-funded project by leading GNS Science and MetService scientists, announced today, will combine existing eruption scenarios with weather forecasting to better predict the likelihood of an area being affected by volcanic ashfall.

The team is developing new models to provide more accurate estimates of how much ash will land, but also when it is likely to arrive.

“Power companies need to know the risk of flashovers due to ash, NZ Transport Agency needs to know if the markings on the roads will become invisible and dairy farmers will be interested how much ash their cows may be ingesting from the grass,” GNS Science volcanologist Yannik Behr said.

In previous eruptions GNS Science has focused on ash deposits, while MetService focused on aviation impacts, as was the case when eruptions at Ruapehu (1995) and Tongariro (2012) significantly affected air travel.

MetService scientist Rosa Trancoso says the two groups have been working together since 2014 to combine modelling forecasts with GNS Science data for New Zealand’s 10 most active volcanoes.

The new project will advance this work by providing the chance of ash being present in a particular area, following an eruption.

“The new tool will be valuable to inform the affected communities about the probability of ash falling in their area, and whether it is light or heavy. The ashfall forecasts are based on high resolution weather and dispersion models that we fine-tune for New Zealand weather,” Dr Trancoso said.

She adds that this new tool has the potential to improve volcanic ash forecasts for the aviation sector as well.

EQC’s Manager of Research Natalie Balfour says the team’s work will bring significant advances in helping communities understand the impact volcanic activity could have during an eruption.

“A better model for ashfall forecasting means decision-makers like emergency managers, councils and homeowners will have more accurate information about the likelihood and severity of ashfall in their area, so that they can take appropriate action.

“Depending on weather, ash can travel long distances and impact communities who may not normally consider themselves at risk from the impacts of an eruption.”