I watched a documentary on Krakatoa and the sound of the eruption could be heard as far away as New Zealand. (The volcano developed cracks that allowed ocean water to come into contact with the magma. The volcano blew itself apart soon thereafter.) If this volcano is on par with what happened then, one might want to put on hold any travel plans to that part of the world for the forseeable future.
The pressure wave from Krakatoa circled the earth three times. It was picked up by the barometer charts all proper Victorians had in their drawing rooms! An excellent book about the eruption is “Krakatoa”, by Simon Winchester. I loved that book.
(ping to our Master of Disasters)
I believe that the sound (pressure wave) passed through the atmosphere and circled the globe twice! Worldwide weather stations noted two "blips" on their barographs, (instruments used to continuously record atmospheric pressure Vs time). The two blips were spaced exactly by the time required for the sound to travel the Earth's circumference.
Regards,
GtG