Time varying crustal anisotropy at Whakaari/White Island volcano

D.M. Mengesha; M.K. Savage; A.D. Jolly; C.J. Ebinger

doi:10.1029/2023gl106473

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Time varying crustal anisotropy at Whakaari/White Island volcano

D.M. Mengesha·M.K. Savage·A.D. Jolly·C.J. Ebinger

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Abstract

Whakaari/White Island has been the most active New Zealand volcano in the 21st century, producing small phreatic and phreatomagmatic eruptions, which are hard to predict. The most recent eruption occurred in 2019, tragically claiming the lives of 22 individuals and causing numerous injuries. We employed shear-wave splitting analyses to investigate variations in anisotropy during quiescence, unrest, and an eruption between 2018 and 2020. We examined spatial and temporal variations in 7972 shear-wave splitting measurements and derived 1402 V p /IV s ratio measurements. Comparing shear-wave splitting parameters from similar earthquake paths across different times indicates that the observed temporal changes are unlikely to result from variations in earthquake paths through media with spatial variability. Instead, these changes may stem from variations in anisotropy over time, likely caused by changes in crack alignment due to stress or varying fluid content.

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Geophysical Research Letters Article

Source-reported bounding extent: -37.53187851005523° to -37.50592081728055° latitude; 177.16503511596648° to 177.19927642935403° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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D.M. Mengesha, M.K. Savage, A.D. Jolly, C.J. Ebinger. 2024-06-08. Time varying crustal anisotropy at Whakaari/White Island volcano. https://doi.org/10.1029/2023gl106473

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Article subject Geophysical Research Letters subject New Zealand place

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