Interpretation of the global tsunami amplitude distribution due to the air pressure waves from the 2022 Hunga Tonga–Hunga Ha`apai volcanic eruption

Abstract

How can the global tsunami amplitude distribution caused by the air pressure waves from the 2022 Tonga eruption be explained? We first propose estimation formulas expressing the maximum possible amplitude and resonance distance of air pressure tsunamis. The estimation formulas clarify both the static and dynamic effects of air pressure waves in the Proudman resonance. Then, based on these formulas, we present hazard maps of the world's oceans for different air pressure wave speeds, considering the water depths. The maps also indicate the excitation length on each air pressure wave path. Using the maps, we can identify ocean regions that trigger tsunamis in response to both air pressure wave speed and period, and therefore explain the global tsunami amplitude distribution, as well as the appearance time of the maximum tide level fluctuations. We also discuss the air pressure tsunamis caused by the historical eruptions. This study will provide information on the sea areas which will generate tsunamis, including meteotsunamis, when air pressure waves occur in the future.