Why in News? The Indian National Centre for Ocean Information Services (INCOIS) forecasted that high sea waves/ swell waves might hit both the west and east coasts of India and Lakshadweep and A&N Islands between May 4 and 5.

What are Swell Waves? These waves are formed by an ocean swell, hence the name swell surge. Ocean swells occur not due to the local winds, but rather due to distant storms like hurricanes or even long periods of fierce gale winds. During such storms, huge energy transfer takes place from the air into the water, leading to the formation of very high waves. Such waves can travel thousands of kilometres from the storm centre until they strike shore. To forecast swell waves, INCOIS launched the Swell Surge Forecast System in 2020 which can give warning seven days in advance.

Which are the Most Vulnerable Regions in India? Usually, states like Kerala witness swell waves as a result of strong winds in the southern part of the Indian Ocean. In March 2024, swell waves led to flooding in several areas of Kerala - the worst affected were Alappuzha, Kollam, and Thiruvananthapuram districts. Such flooding events are called Kallakkadal in Kerala.

What is the Difference Between Swell Waves and Tsunamis?  Unlike swell waves, a tsunami is a series of enormous waves created by an underwater disturbance usually associated with earthquakes occurring below or near the ocean. Tsunamis are around 10 times faster than swell waves. Although both swell waves and tsunamis slow down near the coast, the latter hit land at 30–50 km/h.