The Sound of Collapse.

In August 1883, the island of Krakatoa vanished. The resulting explosion was so violent that the sound wave traveled around the Earth nearly four times.

The 1883 eruption of Krakatoa is a prime example of **Phreatomagmatic activity**. As the volcano erupted, its structural integrity failed, allowing seawater to pour into the magma chamber. The instant conversion of water to steam caused an explosion of unprecedented scale, estimated to be 13,000 times the yield of the Hiroshima bomb.

Acoustics and Global Reach

The final explosion was heard 3,000 miles away in Perth, Australia. Barometers worldwide recorded the atmospheric pressure spike, which traveled at roughly 700 mph. The eruption also injected massive amounts of sulfur dioxide into the stratosphere, causing global temperatures to drop by **1.2°C** for several years and creating vivid, "blood-red" sunsets that were recorded in art across the globe.

Anak Krakatau: The Child

While the original island was destroyed, the volcanic activity did not cease. In 1927, a new island began to emerge from the caldera, aptly named **Anak Krakatau** (Child of Krakatoa). This new cone is an active shield-to-stratovolcano that grows at a rate of roughly five meters per year, serving as a constant reminder that the tectonic forces beneath the Sunda Strait are far from finished.