GS3 PYQ 2021 (Mains Answer Writing ): Earthquakes - Notes | Study Environment & Additional Topics for UPSC CSE - UPSC

Discuss about the vulnerability of India to earthquake related hazards. Give examples including the salient features of major disasters caused by earthquakes in different parts of India during the last three decades. (UPSC MAINS GS3 2021)

Earthquake is sudden shaking of earth surface, while earthquake hazard is anything associated with an earthquake that can affect people’s day-to-day life. Earthquake hazards can range across ground shaking, surface rupture, landslide, liquefaction, tectonic deformation, tsunami etc.
Vulnerability of India to Earthquake-related hazards:

• According to BIS, more than 58.6 percent of the landmass is prone to earthquakes of moderate to very high intensity. The occurrence of the Killari earthquake in 1993 resulted in revision of the seismic zoning in India with the low hazard zone or Seismic Zone I being merged with Seismic Zone II. 
•  Densely populated areas, extensive unscientific constructions and unplanned urbanization have increased risks associated with earthquake hazards. 
• Andaman & Nicobar Islands frequently experience damaging earthquakes due to being situated on an inter-plate boundary. 
• Increasing use of high-technology equipment, susceptible to small vibrations, in industry and academia, or underground utilities for electricity, internet etc. have increased susceptibility to disruption from relatively moderate ground shaking. 
• Regions in Himalayan foothills are vulnerable to liquefaction and landslides due to earthquakes.

Major disasters caused by earthquakes over last three decades

• 1993, Latur: Relatively shallow depth caused large surface damage; causes remain debatable due to lack of plate boundaries in the region.
• 1999, Chamoli: Caused by the thrust fault; resulted in landslides, changes in surface water flow, surface rupture and disconnected valleys.
• 2001, Bhuj: Associated with a reactivated fault, which was previously unknown; impeccable loss of life and property.
• 2004, Indian Ocean Tsunami: Created by under-water seismic activity, created massive waves which flooded coastal areas and islands, causing long-term changes.
• 2005, Kashmir: Caused by severe upthrust of Indian plate against Eurasian plate, it created multiple after-shocks. Infrastructure and communication were disrupted.

India has come a long way on the road to earthquake safety. And yet, much remains to be done before this journey is completed. Creating a system and culture for building safe houses in 21st century India is something not only possible but an absolute necessity.

Topics Covered- Earthquake