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JAMSTEC
Mechanism of a meteorological tsunami reaching the Japanese coast
caused by Lamb and Pekeris waves generated by the 2022 Tonga eruption
1. Key Points
- ◆
- We used numerical simulation to reproduce the meteorological tsunami (*1) sea level change observed near Japan as a result of the large-scale eruption of the Hunga Tonga-Hunga Ha'apai volcano in January 2022.
- ◆
- We found that the meteorological tsunami that reached Japan was excited and amplified
- ◆
- The results suggest the predictability of meteorological tsunamis occurring during submarine eruptions and are expected to contribute to coastal disaster prevention measures.
[Supplemental information]
- *1
- Meteorological tsunami: A phenomenon in which an atmospheric pressure disturbance moves at the same speed as ocean waves, efficiently transferring energy to the ocean (Proudman Resonance) and causing waves with a period similar to that of tsunamis.
- *2
- Lamb wave: A wave in which sparseness or denseness of air density is propagated, similar to a sound wave, and has the property of being constrained by the ground surface and traveling horizontally over long distances at a speed close to the speed of sound.
- *3
- Pekeris wave: A wave because of the natural resonant vibration of the earth's atmosphere, theoretically proposed by Dr. Chaim L. Pekeris in 1937. Unlike the Lamb wave, it has the feature of reversing phase vertically in the atmosphere.
by Lamb (*2) and Pekeris (*3) waves generated by the eruption.
2. Overview
Tatsuo Suzuki is Deputy Group Leader of the Research Center for Environmental Modeling and Application (CEMA), Research Institute for Global Change (RIGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC). Suzuki et al. used numerical simulation to reproduce the meteorological tsunami generated by the Hunga Tonga-Hunga Ha'apai volcano eruption on January 15, 2022 (hereinafter, “Tonga large-scale eruption”), thereby elucidating the mechanism thereof.
In this study, ocean model simulations using the Earth Simulator supercomputer show that Lamb and Pekeris atmospheric waves excited this meteorological tsunami, which was also greatly amplified by Proudman resonance in the deep Northwest Pacific Basin off the east coast of Japan. In addition, we found that it was further amplified by the steep slope of the continental shelf, resulting in large sea level changes along the coast of Japan.
The findings obtained in this study not only deepen physical understanding of the amplification mechanism of meteorological tsunami, but also suggest the predictability of meteorological tsunami associated with volcanic eruptions and are thus important from the perspective of coastal disaster prevention.
This study was supported by MEXT program for the advanced studies of climate change projection (JPMXD0722680395) and Grant-in-Aid for Scientific Research (JP20H05728).
The result was published in Ocean Modelling on December 24 (Japan time).
- Title：
- Mechanism of a meteorological tsunami reaching the Japanese coast caused by Lamb and Pekeris waves generated by the 2022 Tonga eruption
- Authors：
- Tatsuo Suzuki1、Masuo Nakano1、Shingo Watanabe1、Hiroaki Tatebe1、Yuki Takano1,2
- Affiliation：
- 1. Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
2. Atmosphere and Ocean Research Institute, The University of Tokyo - DOI:
- https://doi.org/10.1016/j.ocemod.2022.102153
Contacts:
- (For this study)
- Tatsuo Suzuki, Researcher, Research Institute for Global Change （RIGC）, Research Center for Environmental Modeling and Application (CEMA), Climate Model Development and Application Group (CliM-DAG), JAMSTEC
- (For press release)
- Press Office, Marine Science and Technology Strategy Department, JAMSTEC