On this day in 1883, the most powerful volcanic eruption in recorded history takes place on Krakatau (also known as Krakatoa), a small, uninhabited volcanic island situated west of Sumatra in Indonesia. The explosions were heard 3,000 miles away, ejecting five cubic miles of earth 50 miles into the atmosphere, generating 120-foot tsunamis, and resulting in the deaths of 36,000 people.
The first signs of activity from Krakatau appeared on May 20, 1883, after more than 200 years of inactivity. A German warship sailing nearby reported a towering cloud of ash and dust reaching seven miles high over Krakatau. For the next two months, commercial liners and locals on neighboring Java and Sumatra witnessed similar eruptions. Unaware of the looming disaster, the local population celebrated the volcanic activity with joyful anticipation.
However, on August 27, excitement shifted to terror as Krakatau erupted with such force that it essentially disintegrated, triggering a series of natural calamities that would reverberate worldwide for years.
An enormous explosion on the afternoon of August 26 obliterated the northern two-thirds of the island. As it collapsed into the Sunda Strait, which lies between the Java Sea and Indian Ocean, the erupting mountain unleashed a series of pyroclastic flows (rapidly moving mixtures of gas, ash, and rock) and colossal tsunamis that inundated nearby shorelines.
The following day, beginning at 5:30 a.m., four additional eruptions were catastrophic. The explosions were audible from as far away as 3,000 miles, while ash was thrust up to an astounding height of 50 miles. The fine ash particles spread around the globe, creating breathtaking sunsets and generating an atmospheric layer that reduced worldwide temperatures by several degrees.
Out of the estimated 36,000 fatalities attributed to the eruption, at least 31,000 were due to the tsunamis triggered by the massive portions of the island plunging into the ocean. The tallest of these waves reached heights of 120 feet, inundating nearby islands, uprooting vegetation, and sweeping people out to sea. According to some accounts, an additional 4,500 individuals perished from the heated pyroclastic flows that flowed over the sea, extending as far as 40 miles.
Besides Krakatau, which remains active, Indonesia boasts another 130 active volcanoes, the largest number of any country globally.