Krakatoa Erupts: Explosion Heard 3,000 Miles Away

Four explosions ripped through the volcanic island of Krakatoa on August 27, 1883, the last of them producing the loudest sound in recorded human history. The detonation at 10:02 AM local time was heard 3,110 kilometers away in Perth, Australia, and on the island of Rodrigues near Mauritius, 4,800 kilometers across the Indian Ocean, where residents mistook it for cannon fire from a nearby ship. The eruption killed more than 36,000 people and altered global weather for years. Krakatoa, located in the Sunda Strait between Java and Sumatra, had been erupting intermittently since May 1883, sending ash columns into the sky and generating loud explosions audible in distant cities. Local shipping continued through the strait despite the activity. On August 26, the eruption intensified dramatically. By the morning of August 27, the volcano entered its catastrophic phase. The first explosion at 5:30 AM triggered a tsunami that struck the town of Telok Betong. The second, at 6:44 AM, sent waves east and west. The third and most powerful blast ejected an estimated 25 cubic kilometers of rock and ash, releasing energy equivalent to 200 megatons of TNT, roughly four times the yield of the largest nuclear weapon ever detonated. The final explosion at 10:41 AM collapsed half of Rakata volcano into the sea, generating tsunamis exceeding 30 meters that swept away entire coastal towns on Java and Sumatra. The town of Merak was destroyed by a wave that carried a steamship nearly a mile inland. Pyroclastic flows raced across the surface of the ocean, reaching the Sumatran coast and killing thousands who had believed the water would protect them. The pressure wave circled the Earth seven times, registering on barographs worldwide for five days. Ash propelled 80 kilometers into the atmosphere spread across the globe, producing vivid red sunsets for months. Global temperatures dropped by an estimated 1.2 degrees Celsius and did not return to normal for five years. The eruption destroyed two-thirds of the island, but volcanic activity continued. In 1927, a new island, Anak Krakatau (Child of Krakatoa), emerged from the caldera and has been growing and erupting ever since, a reminder that the forces beneath the Sunda Strait are far from spent.