Kallakkadal

About Kallakkadal

• Kallakkadal refers to coastal flooding caused by swell waves during the pre-monsoon season (April-May) and sometimes during post monsoon along the southwest coast of India.
• Meaning: The term “Kallakkadal,” coined by local fishermen, combines two Malayalam words – “Kallan,” meaning thief, and “Kadal,” meaning sea.
  • When spoken, these words were combined as “Kallakkadal,” signifying the sea arriving like a thief.
  • In 2012, UNESCO formally approved this term.
• Causes/Formation
  • Ocean swell and distant storms: It is caused by waves formed by ocean swells, which originate from distant storms such as hurricanes or prolonged periods of intense gale winds.
    • These storms transfer significant energy from the air into the water, resulting in the formation of extremely high waves.
    • These waves can travel vast distances from the storm centre until they reach the shoreline.
  • Formation: Typically, Kallakkadal occurs due to strong winds in the southern Indian Ocean, where ocean swells are generated.
    • These waves then travel northward, taking around two to three days to reach the coastline.
• Challenges in its Preparedness
  • Kallakkadal happens suddenly without local wind activity, making it hard for coastal residents to receive advance notice.
  • Yet, systems like the Swell Surge Forecast System, initiated by the Indian National Centre for Ocean Information Services (INCOIS) in 2020, provide a seven-day warning.

How Kallakkadal is different from Tsunami?