Monday, August 27, 2007

Catastrophic Krakatoa


The volcano Krakatoa is located on Rakata, an island in the Sunda Strait between Java and Sumatra, Indonesia. Its eruption on this day in 1883 was one of the most catastrophic ever witnessed in recorded history. Until recently, its only known previous eruption was a moderate one in 1680. On the afternoon of Aug. 26, 1883, the first of a series of increasingly violent explosions occurred. A black cloud of ash rose 17 miles (27 kilometers) above Krakatoa. On the morning of the next day, tremendous explosions were heard 2,200 miles (3,540 kilometers) away in Australia. Ash was propelled to a height of 50 miles (80 kilometers), blocking the sun and plunging the surrounding region into darkness for two and a half days.

The drifting dust caused spectacular red sunsets throughout the following year. Pressure waves in the atmosphere were recorded around the Earth, and tsunamis, or tidal waves, reached as far away as Hawaii and South America. The greatest wave reached a height of 120 feet (36 meters) and took 36,000 lives in the coastal towns of nearby Java and Sumatra. Near the volcano masses of floating pumice produced from lava cooled in the sea were thick enough to halt traveling ships. Everything on the nearby islands was buried under a thick layer of sterile ash. Plant and animal life did not begin to reestablish itself to any degree for five years. The volcano was quiet until 1927, when sporadic weaker eruptions began. These tremors have continued into the 1990s.

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