Mount Semeru

In News 

Recently, Indonesia’s Mount Semeru spewed more ash, forcing rescuers to suspend the search for survivors as aerial images.

  • The last time it erupted was in December 2020, forcing thousands of residents to take shelter.

About Mount Semeru

  • The 3,676-meter (12,060-feet) mountain in Lumajang district is the highest volcano on Indonesia’s most densely populated island of Java.
    • Indonesia, an archipelago of more than 270 million people, is prone to earthquakes and volcanic activity because it sits along the Pacific “Ring of Fire,” a horseshoe-shaped series of fault lines.

About Pacific Rim’s “Ring of Fire” region

  • Pacific Rim’s “Ring of Fire” region is also called the Circum-Pacific Belt, it is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.

Pic Courtesy- Geology. 

  • It traces boundaries between several tectonic plates—including the Pacific, Cocos, Indian-Australian, Nazca, North American, and Philippine Plates.
  • It is home to about 75 per cent of the world’s volcanoes and about 90 per cent of its earthquakes.
  • In the realm of Ring of Fire, the tectonic plates overlap at convergent boundaries which results in subduction zones
  • Here, the plate which is below at the convergent boundary is pushed down, or subducted, by the plate above. 
    • As the rock is subducted, it melts and becomes magma. The abundance of magma so near to Earth’s surface gives rise to conditions ripe for volcanic activity.

Volcanism

  • It is the eruption of magma onto the surface of the Earth. It is a phenomenon associated with the surface discharge of molten rock, pyroclastic fragments, or hot water and steam, including volcanoes, geysers, and fumaroles. 
  • A volcano is a vent or fissure in Earth’s crust through which lava, ash, rocks, and gases erupt.