AI 中文总结
本研究针对海气耦合导致难以推断2022年洪加汤加-洪加哈派火山喷发激发力时程的问题，分析15-40mHz的海洋表面重力波，建模后明确了喷发激发的时间、振幅、持续时长及相关现象，为火山喷发研究提供了新途径。
AI 中文摘要
2022年1月15日，洪加汤加-洪加哈派火山发生大规模水下喷发，喷发柱抵达中间层，喷发激发了显著的大气兰姆波，该兰姆波引发了海啸。由于海气耦合导致海啸波形复杂，无法推断激发的力时程。为解决这一问题，我们分析了频率为15至40毫赫兹的海洋表面重力波（OSWs），其因相速度较慢与兰姆波解耦。通过对这些OSWs建模，我们推断激发始于协调世界时4:00，振幅为10^10牛，持续5小时，随后在协调世界时8:40发生一次子事件。观测结果表明，火山口上方海水初始喷出，后续外流激发了5毫赫兹以下的海啸；频率6至15毫赫兹的OSW激发延迟2小时，可能指示海水流入火山口。
英文摘要
On 15 January 2022, a massive underwater eruption occurred at the Hunga Tonga-Hunga Ha'apai Volcano. The plume reached the mesosphere, and the eruption excited a significant atmospheric Lamb wave, which forced the tsunami. The complicated tsunami waveforms due to ocean-atmosphere coupling prevented inferring the force history of the excitation. To address this, we analyze ocean surface gravity waves (OSWs) from 15 to 40 mHz, which are decoupled from the Lamb wave due to their slower phase velocities. Modeling these OSWs, we infer that the excitation started at 4:00 UTC with an amplitude of $10^{10}$ N and lasted for 5 hr, followed by a sub-event at 8:40 UTC. The observations suggest an initial blowout of seawater above the summit and a subsequent outflow that excited a tsunami below 5 mHz. The 2 hr delayed OSW excitation from 6 to 15 mHz may indicate seawater inflow into the crater.
Comments13 pages, 4 figures. Published in Geophysical Research Letters (2024)
Journal refNishida, K., Ichihara, M., Kubota, T., and Tonegawa, T. (2024),Ocean Surface Gravity Waves Excited by the 2022 Eruption of Hunga Tonga-Hunga Ha'apai Volcano, Geophysical Research Letters, 51, e2024GL111983
