Krakatau

Krakatau, also spelled Krakatoa, is a volcanic island group located in the Sunda Strait between Java and Sumatra in Indonesia. The best known event is the cataclysmic eruption of August 1883, one of the most violent eruptions in recorded history. The explosion destroyed much of the island, generated powerful tsunamis, and was heard over thousands of kilometers. The eruption also caused significant global climatic effects, including vivid sunsets and a temporary drop in average temperatures for several years.

Geology and geography: The 1883 eruption left a crescent-shaped caldera and a partly submerged island chain. A new volcanic cone, Anak Krakatau, meaning “Child of Krakatau,” began to emerge within the caldera and rose above sea level in 1927. Today the Krakatoa archipelago comprises several small islands surrounding the central crater, with Anak Krakatau as the active cone. The area sits on the volcanic arc near the boundary of the Indo-Australian and Eurasian tectonic plates.

Recent activity and monitoring: Since 1883, Krakatau has exhibited periodic eruptions, with activity concentrated on Anak Krakatau. The site is closely monitored by Indonesian authorities and international agencies due to the potential for sudden explosions and tsunamis. Notable events include the 2018 flank collapse of Anak Krakatau, which triggered a deadly tsunami in the Sunda Strait. In subsequent years the cone has shown renewed, though generally less explosive, activity.

Impact and significance: Krakatau has had a lasting influence on volcanology and climate science, illustrating the global reach of explosive eruptions. It remains a key site for volcanic research and for observers seeking to understand marine volcanic processes, though access is constrained by ongoing volcanic hazards.