Why in News?
- Semeru volcano was recently erupted in Indonesia’s Eastern Java Island
- Semeru – also known as “The Great Mountain” – is the highest volcano in Java and one of the most active.
- It previously erupted in December, 2021.
- Indonesia, with the maximum number of active volcanoes in the world, is prone to seismic upheaval due to its location on the Pacific’s Ring of Fire.
- Semeru volcano is also part of the Island arcs formed by the subduction of the Indo-Australian plate below Sunda Plate (part of the Eurasian Plate). The trench formed here is called the Sunda trench whose major section is the Java Trench.
- The Ring of Fire, also referred to as the Circum-Pacific Belt, is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
- It traces boundaries between several tectonic plates—including the Pacific, Cocos, Indian-Australian, Nazca, North American, and Philippine Plates.
- They are long, curved chains of oceanic islands associated with intense volcanic and seismic activity and orogenic (mountain-building) processes.
- An island arc typically has a land mass or a partially enclosed, unusually shallow sea on its concave side.
- Along the convex side there almost invariably exists a long, narrow deep-sea trench.
- The greatest ocean depths are found in these depressions of the seafloor, as in the case of the Mariana (deepest trench in the world) and Tonga trenches