Explosive volcanic eruptions produce hazardous atmospheric plumes composed of tephra particles, hot gas and entrained air. Such eruptions are generally driven by magmatic fragmentation or steam expansion. However, an eruption mechanism outside this phreatic–magmatic spectrum was suggested by a sequence of 12 explosive eruptions in May 2018 at Kīlauea, Hawaii, that occurred during the early stages of caldera collapse and produced atmospheric plumes reaching 8 km above the vent. Here we use seismic inversions for reservoir pressure as a source condition for three-dimensional simulations of transient multiphase eruptive plume ascent through a conduit and stratified atmosphere. We compare the simulations with conduit ascent times inferred from seismic and infrasound data, and with plume heights from radar data. We find that the plumes are consistent with eruptions caused by a stomp-rocket mechanism involving the abrupt subsidence of reservoir roof rock that increased pressure in the underlying magma reservoir. In our model, the reservoir was overlain by a pocket of accumulated high-temperature magmatic gas and lithic debris, which were driven through a conduit approximately 600 m long to erupt particles at rates of around 3,000 m³ s⁻¹. Our results reveal a distinct collapse-driven type of eruption and provide a framework for integrating diverse geophysical and atmospheric data with simulations to gain a better understanding of unsteady explosive eruptions.

火山爆发会产生由火山灰颗粒、热气体和夹带空气组成的危险大气羽流。这种喷发通常是由岩浆破碎或蒸汽膨胀驱动的。然而，2018 年 5 月夏威夷基拉韦厄火山发生的 12 次爆炸性喷发暗示了这种潜水岩浆谱之外的喷发机制，这些喷发发生在火山口塌陷的早期阶段，产生的大气羽流达到喷口上方 8 公里。在这里，我们使用储层压力的地震反演作为源条件，对通过管道和分层大气的瞬态多相喷发羽流上升进行三维模拟。我们将模拟与从地震和次声数据推断的管道上升时间以及从雷达数据推断的羽流高度进行比较。我们发现，这些羽流与由踩踏火箭机制引起的喷发是一致的，该机制涉及储层顶板岩石的突然沉降，从而增加了下面岩浆储层的压力。在我们的模型中，储层上覆盖着一堆积累的高温岩浆气体和岩屑，这些气体和岩屑通过大约 600 m 长的管道被驱动，以大约 3,000 m ³ s ^-1的速率喷发颗粒。我们的结果揭示了一种独特的崩塌驱动的喷发类型，并提供了一个将不同的地球物理和大气数据与模拟相结合的框架，以更好地了解不稳定的爆炸性喷发。