The 1883 Krakatoa eruption had a Volcanic Explosivity Index of 6. That rating places it among the largest explosive eruptions in recorded history, reflecting the immense volume of ash, pumice, and volcanic material released during its climax on August 27, 1883.
Krakatoa was an island volcano in the Sunda Strait between Java and Sumatra, then part of the Dutch East Indies. The eruption destroyed more than 70% of the island and caused a caldera to collapse beneath the sea. Several explosions generated destructive tsunamis, which caused most of the estimated 36,417 deaths.
The eruption’s third major explosion was heard in Perth, Australia, more than 3,000 kilometers away, and its atmospheric pressure wave circled the globe multiple times. The blast is often called the loudest sound in recorded history, although the precise measurement and wording depend on how “loudest” is defined.
A common mix-up is confusing the VEI with the eruption’s death toll or tsunami height. VEI measures explosive magnitude, not overall human impact; Krakatoa’s disaster became especially deadly because volcanic explosions and flank collapse produced tsunamis around the densely populated Sunda Strait.