Global water level variability observed after the Hunga Tonga-Hunga Ha'apai volcanic tsunami of 2022

Abstract

Abstract. The eruption of the Hunga Tonga-Hunga Ha'apai volcano on 15 January 2022 provided a rare opportunity to understand global tsunami impacts of explosive volcanism and to evaluate future hazards, including dangers from “volcanic meteotsunamis” (VMTs) induced by the atmospheric shock waves that followed the eruption. The propagation of the volcanic and marine tsunamis was analyzed using globally distributed 1 min measurements of air pressure and water level (WL) (from both tide gauges and deep-water buoys). The marine tsunami propagated primarily throughout the Pacific, reaching nearly 2 m at some locations, though most Pacific locations recorded maximums lower than 1 m. However, the VMT resulting from the atmospheric shock wave arrived before the marine tsunami and propagated globally, producing water level perturbations in the Indian Ocean, the Mediterranean, and the Caribbean. The resulting water level response of many Pacific Rim gauges was amplified, likely related to wave interaction with bathymetry. The meteotsunami repeatedly boosted tsunami wave energy as it circled the planet several times. In some locations, the VMT was amplified by as much as 35-fold relative to the inverse barometer due to near-Proudman resonance and topographic effects. Thus, a meteotsunami from a larger eruption (such as the Krakatoa eruption of 1883) could yield atmospheric pressure changes of 10 to 30 mb, yielding a 3–10 m near-field tsunami that would occur in advance of (usually) larger marine tsunami waves, posing additional hazards to local populations. Present tsunami warning systems do not consider this threat.

Volcanic Eruption Triggers a Rare Meteotsunami in the Indian Ocean

“…A ∼1 cm spike was visible at 13:20 hr in the BoB2, and ∼3 hr later, a ∼2 cm spike occurred in the AS. These spikes in BPRs correspond to the fast propagation of the first Lamb wave over the ocean (Devlin et al., 2023). This was confirmed by estimating the speed of the wave as 294.39 m s −1 and 305.32 m s −1 from the BPR pairs, (BoB2, BoB1) and (BoB1, AS), respectively.…”

“…These results are very similar to the recent observation along the Japanese coast, that meteotsunami were not observed at water depths shallower than 2,000 m (Tonegawa & Fukao, 2022). Notably, the Froude number is significantly greater than 1 in the BoB, impeding a forced wave amplification (Proudman resonance), in contrast to the Japan coast (Devlin et al., 2023).…”

Australian atmospheric pressure and sea level data during the 2022 Hunga-Tonga Hunga-Ha’apai volcano tsunami

“…Compared with MSLP and sea level data for the HTHH volcanic tsunami that is already openly available 6 , 9 , 10 , the data herein 8 greatly increases the density of observations near Australia.…”

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

“…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.…”