TIMING Analysis of the Multiple Passages of the Pressure Wave Generated by the 2022 Hunga Tonga-Hunga Ha’apai and Comparison with the 1883 Krakatoa Pressure Wave

The Hunga Tonga-Hunga Ha’apai (HTHH) eruption of 15 January 2022 was an exceptional event by the period, magnitude, and duration of propagation of the atmospheric waves it generated, which circled the Earth multiple times. This event, taking into account the magnitude of the atmospheric pressure waves, is comparable only to the Krakatoa eruption of 1883. To compare both eruptive sequences, a method similar to the analysis of the timing of the arrival of multiple phases at barometric stations, as reported in (Strachey, R., Stokes G.G., Scott, R.H. (1888). On the air waves and sound caused by the Krakatoa eruption of August 1883, in “The eruption of Krakatoa and subsequent phenomena,” Symons, G. J. (ed.). Report of the Krakatoa Committee of the Royal Society (Trübner and Co., London)) for Krakatoa, was used. Since the HTHH volcanic event gave rise to the only volcanic pressure wave known to have circled within the Earth’s atmosphere multiple times in the last 139 years, it is of interest to perform similar timing statistics on the multiple passages of the waves at stations that recorded them. A review of the Krakatoa analysis and a comparison with the HTHH are presented, with possible implications on the physical parameters affecting its speed of propagation. Changes in the global state of the atmosphere during the interval between the two events may also explain some of the differences observed.