The loudest sound in recorded history was heard 3,000 miles away. The explosion killed 36,000 people, cooled the entire planet, and may have inspired The Scream.
On August 27, 1883, the volcanic island of Krakatoa in the Dutch East Indies (now Indonesia) exploded with a force estimated at 13,000 times the power of the Hiroshima atomic bomb. The eruption destroyed more than two-thirds of the island. The main explosion registered a Volcanic Explosivity Index of 6 — an event of this magnitude occurs only a few times per century.
The sound produced by the explosion was the loudest ever recorded in human history. It was heard in Perth, Australia, 3,110 kilometers away — roughly the distance from London to Moscow — and near Rodrigues Island off Mauritius, nearly 5,000 kilometers distant. The acoustic pressure wave circled the globe more than three times, measurable on barographs worldwide for days afterward.
The immediate death toll was staggering: at least 36,417 people killed, the vast majority by tsunamis generated when the island collapsed. Waves reached heights of 24 to 46 meters — up to 15 stories — and swept entire coastal villages off the map. Some bodies were found floating in the Indian Ocean more than a year later, kept buoyant by the volcanic pumice around them.
The pyroclastic flows — superheated clouds of gas and rock moving at over 100 km/h — crossed the ocean surface for up to 80 kilometers, killing people on the shores of neighboring islands. Survivors described how day became absolute night as ash and pyroclastic material blotted out the sun entirely. One coastal settlement, Merak, lost nearly its entire population in minutes.
The atmospheric effects were global. Krakatoa ejected approximately 20 cubic kilometers of debris into the stratosphere. Sulfur dioxide particles circled the planet, causing global temperatures to drop by about 0.4°C for the following year. More visibly, they scattered sunlight in ways that produced spectacular red sunsets worldwide for months — observed and documented across Europe, the Americas, and Asia.
The British artist William Ascroft made thousands of sketches documenting the vivid, lurid sunsets over London in the months after the eruption. Some scholars argue that the blood-red sky in Edvard Munch's 1893 painting The Scream — completed a decade later — reflects a memory of these Krakatoa-inspired skies that Munch saw as a young man in Norway. The connection has not been definitively proven, but the timing and description match.
Krakatoa also produced the first scientific identification of a high-altitude global wind pattern: the 'equatorial smoke stream' that carried its ash around the planet in roughly two weeks. This observation contributed to the later understanding of what we now call the jet stream. The eruption became one of the first global natural events to be studied and reported in near-real time, thanks to the telegraph.
The island of Krakatoa was not finished. In 1927 — 44 years after the original eruption — a new volcanic cone emerged from the water where the island had been and continued growing. Named Anak Krakatau (Child of Krakatoa), it has been intermittently active ever since. In 2018, a partial collapse of Anak Krakatau generated a tsunami that killed more than 400 people in Indonesia, demonstrating that the story of Krakatoa is far from over.