The andesitic volcanic island Whakaari (White Island) explosively erupted on 9 December 2019. White Island is a popular tourist destination, and 47 people were on the island at the time. Twenty-one died, and a further twenty-six people suffered injuries. Persistent scatterer (PS) interferometry with synthetic aperture radar (SAR) is a powerful satellite-based remote sensing tool to monitor land deformation associated with volcanic unrest. This study examined deformation on White Island over the eruption period and identified a dome on the crater floor that inflated for 15 months preceding the eruption, consistent with a previous analysis of TerraSAR-X satellite data. Results here show the dome began to collapse after 25 November, about two weeks prior to the eruption. This finding has immediate relevance for ongoing hazard monitoring at White Island and other volcanoes worldwide where sudden dome contraction may presage an eruption.

安第斯山脉的火山岛华卡里（白岛）于2019年12月9日爆发。白岛是一个受欢迎的旅游胜地，当时岛上有47人。21人死亡，另外26人受伤。带有合成孔径雷达（SAR）的持久散射（PS）干涉测量法是一种功能强大的基于卫星的遥感工具，可以监视与火山爆发相关的土地变形。这项研究检查了喷发期间白岛的变形，并确定了喷发前火山口底部膨胀了15个月的圆顶，这与先前对TerraSAR-X卫星数据的分析一致。此处的结果显示，圆顶在爆发前约两周的11月25日之后开始塌陷。