Abstract. Extreme, tsunami-like wave runup events in the absence of earthquakes or landslides have been attributed to trapped waves over shallow bathymetry and long waves created by atmospheric disturbances. These runup events are associated with inland excursions of hundreds of meters and periods of minutes. While the theory of radiation stress implies that nearshore energy transfer from the carrier waves to the infragravity waves can also lead to very large runup, there have not been observations of runup events induced by this process with magnitudes and periods comparable to the other two mechanisms. This work presents observations of several runup events in the U.S. Pacific Northwest that are comparable to extreme runup events related to trapped waves and atmospheric disturbances. It also discusses possible generation mechanisms and shows that energy transfer from incident waves to bound infragravity waves is a plausible generation mechanism. In addition, a method to predict and forecast extreme runup events with similar characteristics is presented.

中文翻译：

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美国太平洋西北海岸的极端波上升事件观测

摘要。在没有地震或滑坡的情况下，极端的，类似海啸的波浪上升事件被归因于浅测深处的滞留波和大气扰动造成的长波。这些暴发事件与数百米和几分钟的内陆旅行有关。虽然辐射应力理论暗示了近海能量从载波到次重力波的转移也可能导致非常大的上升，但是还没有观察到由该过程诱发的上升事件，其幅度和周期与其他两种机制相当。这项工作提供了对美国太平洋西北部几个暴发事件的观察结果，这些事件可与与被困波和大气干扰有关的极端暴发事件相提并论。它还讨论了可能的生成机制，并表明从入射波到束缚的非重力波的能量转移是一个合理的生成机制。此外，提出了一种预测和预测具有相似特征的极端加速事件的方法。