When this explosive noise occurred in August, 1883, it equaled the sound of 3,000 atomic bombs, could be heard 2,200 miles away, and debris was scattered 4000 miles away. What was it that exploded?

The cataclysmic event of August 1883 (Review) was the eruption of Krakatoa, a volcanic island in the Sunda Strait of Indonesia. On the morning of August 27th, the volcano unleashed a series of four colossal explosions, culminating in a final blast that is considered the loudest sound ever recorded in modern history. The noise was so powerful that it ruptured the eardrums of sailors 40 miles away and was distinctly heard as "the roar of heavy guns" by people in Australia, over 2,200 miles from the source. The atmospheric pressure wave it created was detected by barographs as it circled the globe multiple times.

The eruption's immediate impact was devastating, as it triggered a series of massive tsunamis that obliterated hundreds of coastal villages and resulted in over 36,000 deaths. The long-term effects were felt worldwide. An enormous plume of ash and gas was ejected into the stratosphere, causing average global temperatures to dip for several years. This atmospheric debris also produced spectacular, intensely colored sunsets and sunrises across the globe for the next three years, a phenomenon that captivated and puzzled people from London to New York. The original island was almost entirely destroyed, but its legacy lives on as a stark example of Earth's raw power.