The 1883 eruption of Krakatoa, a volcanic island in the Sunda Strait between Java and Sumatra, was one of the most violent volcanic events of the modern era. Its climax on 27 August produced what is often called the loudest sound in recorded history and drove tsunamis that drowned tens of thousands of people on the surrounding coasts. Carried within hours by the new global telegraph network, the disaster became arguably the first natural catastrophe the whole world followed in near-real time, and its high-altitude veil of ash and gas cooled the planet slightly and painted vivid red skies around the globe for months.
On the morning of 27 August 1883, much of an island in the Sunda Strait blew apart, and the planet heard it. The largest blast is often called the loudest sound in recorded history. People reported hearing it nearly 5,000 kilometres away, on an island near Mauritius, where it was logged as distant gunfire. Its pressure wave was traced circling the Earth several times on barometers in distant cities. Yet the noise was not the killer. The eruption shoved walls of seawater across the strait, and those tsunamis drowned tens of thousands along the low coasts of Java and Sumatra. What made Krakatoa singular was not only its violence but its timing. Undersea telegraph cables flashed the news worldwide within a day, so newspapers everywhere followed the disaster almost as it happened. For the first time, a faraway catastrophe became something the whole world experienced together.