Mapping
Context: A series of intense volcanic eruptions at Indonesia’s Mount Anak Krakatau blanketed Jakarta and surrounding provinces in dense ash clouds.
About Mount Anak Krakatau:
What it is?
- An active volcanic island and stratovolcano featuring a pyroclastic cone. Its name translates to Child of Krakatoa in Indonesian.
Located in: Situated in the Sunda Strait between the major islands of Java and Sumatra, within the protected waters of Ujung Kulon National Park.
Formation and Origin:
- Originated within the deep marine caldera created by the catastrophic 1883 VEI-6 eruption of Krakatoa, which annihilated two-thirds of the original island.
- Following submarine eruptive activity that started in early 1927, repeated cycles of basaltic accumulation breached the ocean surface, permanently rising above sea level on August 11, 1930.
Key Characteristics:
- Tectonic Setting: Located on the Pacific Ring of Fire, roughly 700 km north of the Sunda Trench where the oceanic Indo-Australian Plate subducts beneath the continental Sunda Plate.
- Rapid Geomorphic Growth: A textbook Somma-stratovolcano system that has grown rapidly through frequent Strombolian and Vulcanian eruptions, historically adding 7 to 9 meters of height per year before its major collapse.
- Complex Igneous Petrography: Composed primarily of andesite, dacite, and basaltic lava flows interbedded with thick pyroclastic fall and cinder deposits.
- Flank Collapse & Tsunami Hazards: The volcanic edifice is structurally volatile due to steep caldera-edge underwater topography; a major southwest flank collapse in December 2018 triggered the deadly Sunda Strait tsunami.
Implications:
- Fine volcanic ash can melt inside jet engines, damage turbines and block sensors, forcing flight cancellations and temporary airspace closures.
- Eruptions near the Sunda Strait can release pumice and volcanic debris, reduce visibility and disrupt this key shipping route between the Indian Ocean and Java Sea.
