On this day August 27, 1883
Four enormous explosions from the volcanic eruption of Krakatoa generated tsunamis that destroyed many settlements on Java and Sumatra in Indonesia.
The explosions took place at 05:30, 06:44, 10:02, and 10:41 local time. The explosions were so violent that they were heard 3,500 km (2,200 mi) away in Perth, Western Australia and the Indian Ocean island of Rodrigues near Mauritius, 4,800 km (3,000 mi) away, where they were thought to be cannonfire from a nearby ship.
Each was accompanied by very large tsunamis, which are believed to have been over 30 meters (100 ft) high in places. A large area of the Sunda Strait and a number of places on the Sumatran coast were affected by pyroclastic flows from the volcano.
The pressure wave generated by the colossal final explosion radiated from Krakatoa at 1,086 km (675 mi). It was so powerful that it shattered the eardrums of sailors on ships in the Sunda Strait and caused a spike of more than two and half inches of mercury in pressure gauges attached to gasometers in the Jakarta gasworks, sending them off the scale.
The pressure wave radiated across the globe and was recorded on barographs all over the world, which continued to register it up to 5 days after the explosion. Barograph recordings show that the shockwave from the final explosion reverberated around the globe 7 times in total. Ash was propelled to a height of 80 km (50 mi).