Miller CA, Taylor-Offord S, Sherburn S, Magill CR, Pastor-Paz J. 2022. Revised threat assessment of New Zealand’s volcanoes. Lower Hutt (NZ): GNS Science. 32 p. (GNS Science report; 2022/41). doi:10.21420/AQWM-ZR12.
Abstract
We present a revised version of the New Zealand Volcano Early Warning System (NZVEWS) volcano threat assessment, updating the 2012 assessment. The purpose of this assessment is to guide future investment in volcano monitoring instrumentation for New Zealand’s active volcanoes. This report ranks New Zealand’s volcanoes by an internationally recognised threat assessment method, which we modify for New Zealand conditions. The underlying assumption is that higher-threat volcanoes warrant higher levels of instrumentation. In this revised assessment, we include new exposure factors (gross domestic product [GDP] exposure and short-term visitors), as well as introduce a new vulnerability metric based on the 2018 New Zealand Deprivation Index. We group the threat ranking and vulnerability-modified threat rankings of volcanoes into ‘high’, ‘medium’ and ‘low’ groups based on 33% quantile distribution of threat scores. Where discrepancies between threat ranking and vulnerability-modified threat ranking exist, we take the higher value for final group assignment. Ōkataina Volcanic Centre, Auckland Volcanic Field, Taranaki, Ruapehu, Taupō and Tongariro/ Ngauruhoe are the highest-threat volcanoes in New Zealand and warrant prioritisation for future network upgrades pending the outcome of the second stage of this work, which investigates instrumentation requirements for each threat-level group. (The authors)
