Introduction:
Earthquakes, natural phenomena characterized by sudden tremors of the Earth’s surface, give rise to a spectrum of hazards that can significantly impact daily life. These hazards encompass ground shaking, surface rupture, landslides, liquefaction, tectonic deformation, and even tsunamis. In the context of India, a nation susceptible to such seismic events, understanding and addressing these earthquake-related vulnerabilities is of paramount importance.
Body:
Extent of Vulnerability:
- Over 58.6% of India’s landmass is prone to earthquakes of varying intensities, as indicated by the Bureau of Indian Standards (BIS).
- The seismic zoning in India was revised following the Killari earthquake in 1993, resulting in the merger of low hazard zones (Seismic Zone I) with moderate hazard zones (Seismic Zone II).
Urbanization and Population Pressure:
- Urbanization characterized by unscientific constructions and unplanned growth has amplified the risks associated with earthquake hazards.
- Densely populated areas face increased vulnerabilities due to inadequate infrastructure and emergency response mechanisms.
Andaman & Nicobar Islands’ Susceptibility:
- These islands, situated on an inter-plate boundary, frequently experience damaging earthquakes.
- The geological setting makes them prone to seismic activities that can lead to considerable disruption.
Technological Infrastructure Susceptibility:
- The proliferation of high-tech equipment, sensitive to even minor vibrations, in industry, academia, and utilities exposes India to disruptions from moderate ground shaking.
- Underground utilities for electricity and internet services are particularly vulnerable.
Himalayan Foothills Vulnerability:
- The regions along the Himalayan foothills are prone to liquefaction and landslides, which earthquakes can trigger.
- The unstable geological conditions make these areas susceptible to significant damage.
Examples of Major Earthquake Disasters:
- 1993 Latur Earthquake: Shallow depth, 6.2 magnitude; led to large surface damage; uncertain causes due to lack of plate boundaries.
- 1999 Chamoli Earthquake: Thrust fault; caused landslides, altered surface water flow, and created disconnected valleys.
- 2001 Bhuj Earthquake: Reactivated fault, previously unknown; resulted in loss of life and property due to unchecked construction.
- 2004 Indian Ocean Tsunami: Underwater seismic activity led to massive coastal flooding and long-term changes in affected regions.
- 2005 Kashmir Earthquake: 7.6 magnitude; upthrust of Indian plate against Eurasian plate; disrupted infrastructure and communication.
Conclusion:
India’s susceptibility to diverse earthquake hazards necessitates astute planning and preparedness. Learning from instances like the post-2001 Bhuj earthquake reconstruction underscores the importance of long-term strategies in mitigating the impact of seismic events. As India continues to evolve and urbanize, strategic measures must be taken to bolster infrastructure, enhance awareness, and foster resilience against earthquake-related vulnerabilities.