When this Indonesian volcanic island exploded in August 1883, it blew the island apart and caused a tidal wave that killed more than 36,000 people. What was it?

The catastrophic event described refers to the 1883 eruption of Krakatoa, also known as Krakatau, an Indonesian volcanic island located in the Sunda Strait between Java and Sumatra. On August 26-27, 1883, Krakatoa experienced a series of immense explosions, with the climactic blast on August 27 being one of the most violent volcanic events in recorded history. This cataclysmic eruption obliterated over seventy percent of the island, causing it to collapse into a caldera. The most devastating consequence was the generation of colossal tsunamis, some reaching heights of up to 40 meters (120 feet), which crashed into the coastlines of Java and Sumatra. These waves were responsible for the vast majority of the over 36,000 recorded fatalities, wiping out numerous coastal villages.

The eruption's power was truly astounding, producing the loudest sound ever recorded in history. The final explosion on August 27 was heard thousands of miles away, as far as Western Australia and Mauritius, and its atmospheric shockwaves circled the globe at least seven times over the following five days. Beyond the immediate destruction, Krakatoa's eruption injected massive amounts of ash and sulfur dioxide into the atmosphere, leading to a noticeable drop in global temperatures for the following year and creating spectacular, fiery sunsets observed worldwide. This atmospheric phenomenon even inspired the occurrence of "blue moons" as volcanic particles filtered sunlight.

The legacy of the 1883 eruption continues today. The remains of Krakatoa lay dormant for decades until new volcanic activity began in the 1920s, eventually forming a new island volcano within the caldera. This "Child of Krakatoa," known as Anak Krakatau, has continued to grow and erupt periodically, serving as a powerful reminder of the immense forces that shaped its parent island and continue to shape the Earth.