How It Works

Why Krakatoa was heard across Earth


Krakatoa’s super-explosive 1883 eruption was so loud because of its pressure wave reverberating around the planet over seven times. This was due to the colossal energy release from the volcano, which was equal to over 200 megatons of TNT – roughly four times as much as the largest-ever detonated nuclear bomb! Indeed, the radiated pressure wave was so high that it ruptured the eardrums of sailors in the Sunda Strait in Indonesia, generated tsunamis almost 40 metres (131 feet) high and caused a mercury spike in pressure gauges attached to gasometers in the Batavia (modern-day Jakarta) gasworks, located nearly 160 kilometres (100 miles) away.