Destructive potential of planetary meteotsunami waves beyond the Hunga volcano eruption (Tonga)

Abstract

Worldwide tsunamis generated by atmospheric waves -or planetary meteotsunami waves -are extremely rare events occurring during supervolcano explosions or asteroid impacts. Recently, such waves have been globally recorded after the Hunga volcano eruption (Tonga) but did not pose any serious danger to the coastal communities. However, this study highlights that the mostly ignored destructive potential of planetary meteotsunami waves can be compared to the well-studied tsunami hazards. Through simple numerical experiments we indeed prove that meteotsunami surges above 1.00 m can be generated along more than 7 % of the world coastlines by atmospheric waves either more intense or slower than during the Hunga event. Consequently, the global meteotsunami hazards should now be properly assessed to prepare for the next big volcanic eruption or asteroid impact.

Observational study of the heterogeneous global meteotsunami generated after the Hunga Tonga–Hunga Ha’apai Volcano eruption

“…The numerical simulations carried out by Refs. 21 , 22 show that waves of a few cm were generated in the open ocean during the passage of the atmospheric disturbance. The simulations also show that these waves were organized in several wave fronts, since when the atmospheric wave overtakes the ocean waves the latter are decoupled and travel at a lower speed as tsunami waves 16 , 21 .…”

“…19 tried to relate the timings and amplitudes recorded by tide gauges located worldwide with the different generating processes outlined above; however, they did not examine in detail the causes of the observed spatial heterogeneity. Other works have performed global numerical simulations of the atmosphere-ocean coupling that resulted in the ocean long waves observed outside the Pacific Ocean 21,22 ; however, these studies cannot reproduce the sea level oscillations observed by coastal tide gauges, because this would require high resolution simulations with very high-resolution bathymetries near the coast (which is prohibitive for global-scale simulations).Here we try to explain the spatial heterogeneity of the observed sea level response at the coast through an exhaustive analysis of atmospheric pressure and sea level observations recorded worldwide. On one hand, we intend to give an overall description of the observations to highlight the global dimension of both, the atmospheric pressure disturbance and the sea level response.…”

“…19 tried to relate the timings and amplitudes recorded by tide gauges located worldwide with the different generating processes outlined above; however, they did not examine in detail the causes of the observed spatial heterogeneity. Other works have performed global numerical simulations of the atmosphere-ocean coupling that resulted in the ocean long waves observed outside the Pacific Ocean 21,22 ; however, these studies cannot reproduce the sea level oscillations observed by coastal tide gauges, because this would require high resolution simulations with very high-resolution bathymetries near the coast (which is prohibitive for global-scale simulations).…”