On the evening of 15 January 2022, the Hunga Tonga-Hunga Ha’apai volcano¹ unleashed a violent underwater eruption, blanketing the surrounding land masses in ash and debris^{2, 3}. The eruption generated tsunamis observed around the world. An event of this type last occurred in 1883 during the eruption of Krakatau⁴, and thus we have the first observations of a tsunami from a large emergent volcanic eruption captured with modern instrumentation. Here we show the explosive eruption generated waves through multiple mechanisms, including: 1) air-sea coupling with the initial and powerful shockwave radiating out from the explosion in the immediate vicinity of the eruption, 2) the collapse of the water-cavity created by the underwater explosion, and 3) air-sea coupling with the air-pressure pulse that circled the earth multiple times, leading to a global tsunami. In the near-field, the tsunami impacts are strongly controlled by the water-cavity source, while the far-field tsunami, which was unusually persistent, can be largely described by the air-pressure pulse mechanism. Catastrophic damage in some harbors in the far-field was averted by just tens of centimeters, implying that a modest sea level rise combined with a future, similar event would lead to a step-function increase in impacts on infrastructure. Piecing together the complexity of this event has broad implications to the hazard in similar geophysical settings, suggesting a currently neglected source of global tsunamis.

2022 年 1 月 15 日晚上，洪加汤加-洪加哈帕伊火山^{1 号引发了剧烈的水下喷发，火山灰和碎片2、3}覆盖了周围的陆地。火山爆发引发了世界各地观察到的海啸。此类事件上一次发生在 1883 年 Krakatau ^{4喷发期间}，因此我们首次观测到了现代仪器捕获的大型紧急火山喷发引发的海啸。在这里，我们展示了爆炸性喷发通过多种机制产生的波，包括：1）海气耦合与从喷发附近的爆炸中辐射出的初始和强大的冲击波，2）由水下爆炸，以及 3）海气耦合与多次环绕地球的气压脉冲，导致全球海啸。在近场，海啸冲击受水腔源的强烈控制，而远场海啸异常持续，主要可以通过气压脉冲机制来描述。远场一些港口的灾难性破坏仅被避免了数十厘米，这意味着海平面适度上升以及未来类似事件将导致对基础设施的影响逐步增加。将这一事件的复杂性拼凑起来对类似地球物理环境中的危害具有广泛的影响，这表明目前被忽视的全球海啸来源。