NEPAL EARTHQUAKE (Syllabus: GS Paper 3 – Disaster Management)

Context: The Prime Minister of India has expressed deep grief over the loss of lives due to the earthquake in Nepal.

Nepal’s Seismic Vulnerability

• Location: Nepal sits atop a convergent boundary, where the Indian and Eurasian tectonic plates collide, leading to the accumulation of stress and strain in the crust. 
• This pressure is eventually released in the form of earthquakes.
• Subduction Zone: Nepal is also situated in a subduction zone. This subduction process further amplifies the stress and strain within the crust, contributing to the occurrence of earthquakes in Nepal.
• Poor building construction practices: Many structures in Nepal are constructed with unreinforced masonry, which lacks strength and can easily crumble during an earthquake.

Earthquake

• About: An earthquake is a violent and abrupt shaking of the ground, caused by movement between tectonic plates along a fault line in the earth's crust. 
• Earthquakes can result in ground shaking, soil liquefaction, landslides, fissures, avalanches, fires, and tsunamis.
• Focus and Epicentre: The initial point of energy release is the focus, and the surface point above it is the epicenter.
• Foreshocks and Aftershocks: Major earthquakes often involve minor aftershocks and sometimes have preceding foreshocks.
• Swarms: Clusters of small earthquakes are called swarms and often indicate impending volcanic activity.
• Distribution of Earthquakes: Circum-Pacific Belt, Alpine Belt, Oceanic Ridges and Rift Valleys.