• Ville Miettinen

Pressure wave of Tonga volcano

My observatory weather station captured something really intresting, a sudden spike in atmospheric pressure of 2 hPa. After a bit of searching I realized that it was caused by a volcanic erruption near Tonga archipelago in the southern Pacific Ocean. The first shockwave can be seen around 20.00 local time and the other edge travelled from other side of the globe and that can be seen just before 06.00 as a weaker disturbance.

Other amateur astronomers noticed this too in their weather stations and L. Kangas mapped this great animation from FMI open data. You can see the pressure waves go from north to south and then a weaker pressure increase from south to north. You can see it here. Satelite imagery also shows the strenght of the explosion and the start of the shockwave as the volcano errupts.