A Tsunami (a Japanese word meaning “harbour wave”) is a series of giant ocean waves caused by a large-scale, sudden displacement of water, usually in an ocean.

Causes of Tsunami

  • Undersea Earthquakes (Most Common): Occur primarily at convergent plate boundaries (subduction zones) where one tectonic plate slides under another. The sudden vertical displacement of the seabed displaces the water column above.
  • Underwater Landslides: Massive slumping of marine sediments or volcanic flanks displaces water rapidly.
  • Volcanic Eruptions: Submarine eruptions or violent coastal eruptions (e.g., the Hunga Tonga-Hunga Ha’apai eruption in 2022) can trigger tsunamis through explosive displacements or caldera collapses.
  • Meteorite Impacts: Rare, but highly catastrophic potential causes.

Vulnerable Regions

  • Global
    • The Pacific “Ring of Fire”: Around 80% of the world’s tsunamis occur here due to intense tectonic activity and subduction zones (e.g., the 2011 Tohoku Tsunami in Japan).
  • India
    • Andaman-Sumatra Subduction Zone: Triggered the catastrophic December 26, 2004, Indian Ocean Tsunami.
    • Makran Subduction Zone: Located in the Arabian Sea (off the coast of Pakistan/Iran).

Management and Mitigation

  • India
    • ITEWS (Indian Tsunami Early Warning System): Established in 2007, it is operated by the Indian National Centre for Ocean Information Services (INCOIS) in Hyderabad.
  • Global

 

Source: The Indian Express

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