Observations and simulations of the meteotsunami generated by the Tonga eruption on 15 January 2022 in the Mediterranean Sea

Abstract

Summary The 15th January 2022 eruption of the Hunga-Tunga volcano generated a Lamb pressure wave propagating all over the globe and triggering a tsunami throughout the planet. A first atmospheric wave arrived 16 hours after the eruption on the French Mediterranean coasts and propagated southward. A second one originating from Africa was observed four hours later with an attenuated amplitude. The first wave can be roughly defined either by a N-wave or a sinusoid signal with a period close to 50 min and an amplitude of 130 Pa. In the Mediterranean Sea, the tsunami was recorded by almost all standard coastal tide gauges or pressure gauges. The French tide gauge stations recorded water waves with amplitudes ranging from a few cm to 10 cm and with periods ranging from 10 min to 1 hour. Numerical simulation of the tsunami is performed by the operational code Taitoko for different atmospheric sources. Nonlinear shallow water equations are solved by a finite-difference method, using the nested multigrid approach. The tsunami is generated by calculating analytically the atmospheric pressure gradient in the momentum equations. Comparisons of time series between numerical solutions and records are satisfactory for most tide-gauges along the French Mediterranean coast. Sensitivity analysis on the atmospheric source and on the resolution is performed. For most tide-gauge stations, numerical results show that the wave forms depend first on local resonance phenomena.

The 2022 Tonga Tsunami on the Pacific and Atlantic Coasts of the Americas

“…The intense atmospheric Lamb waves generated by the volcanic eruption propagated over the globe with the speed of sound, exciting sea level oscillations (“atmospheric tsunami waves”) in the open ocean and in shelf zones (Kulichkov et al., 2022; Omira et al., 2022). The Lamb waves were the main reason that Tonga tsunami waves were observed in such remote and sheltered areas as the Sea of Japan (Tsukanova & Medvedev, 2022), the Mediterranean Sea (Heinrich et al., 2023) and the Gulf of Mexico.…”

“…In addition to the globe‐circling atmospheric waves, the Tonga‐Hunga volcanic explosion produced tsunami waves that were recorded throughout the entire World Ocean, including the Pacific coasts of Chile, the United States, New Zealand and Japan, as well as the Caribbean, Mediterranean and Black seas (cf. Borrero et al., 2023; Carvajal et al., 2022; Devlin et al., 2023; Heinrich et al., 2023; Imamura et al., 2022; Santellanes et al., 2023; Tanioka et al., 2022; Tsukanova & Medvedev, 2022). A unique feature of the tsunami waves measured by coastal tide gauges and open‐ocean bottom pressure recorders was the dual forcing mechanism that sent both “oceanic” tsunami waves—induced directly by the eruption and radiating outward from the source at the longwave speed of ∼200 m/s—and atmospheric Lamb waves that circled the globe at the speed of sound of ∼314 m/s.…”

One‐Minute Resolution GOES‐R Observations of Lamb and Gravity Waves Triggered by the Hunga Tonga‐Hunga Ha'apai Eruptions on 15 January 2022

“…The global propagation of this broad far-field atmospheric pressure pulse was well reproduced by Amores et al (2022), who introduced an instantaneous sea level perturbation in a shallow water ocean model as well as by Watanabe et al (2022), who imposed an instantaneous hot anomaly over the volcano in an atmospheric general circulation model. The atmospheric Lamb wave triggered a meteotsunami, the accurate numerical simulation of which also required the imposition of such long-period and long-wavelength pressure pulses as forcing (Heinrich et al, 2023;Kubota et al, 2022;Suzuki et al, 2023;Winn et al, 2023;Yamada et al, 2022).…”

“…(2022), who imposed an instantaneous hot anomaly over the volcano in an atmospheric general circulation model. The atmospheric Lamb wave triggered a meteotsunami, the accurate numerical simulation of which also required the imposition of such long‐period and long‐wavelength pressure pulses as forcing (Heinrich et al., 2023; Kubota et al., 2022; Suzuki et al., 2023; Winn et al., 2023; Yamada et al., 2022).…”

“…Studies analyzing surface pressure records or numerically simulating the atmospheric waves and the triggered meteotsunamis arrived at similar or even longer Lamb wavelengths and periods. The far-field envelope of the complex pressure wave packet can be roughly approximated by an N-wave or a positive triangular pulse of 400-900 km width and 20-50 min duration (Heinrich et al, 2023;Kubota et al, 2022;Matoza et al, 2022;Vergoz et al, 2022;Watada et al, 2023;Winn et al, 2023).…”