The pressure wave generated by Tonga's volcanic eruption was clearly observed three times (at least) by our weather station on Inis Meáin. Prof. Emile Okal estimated the arrival times at 18:45, 01:35+1 and 06:20+2 with his model. Note the change in polarity for the second wave. Phases advances are generated when the wave goes through the antipodes.

Tonga All Circled