Why is it in the news?

• Swell waves, locally referred to as ‘Kallakkadal’ in Kerala, are a phenomenon characterized by inundation of coastal areas in central and southern districts of the state.

More about the news

• The term ‘Kallakkadal’ is colloquially used by Kerala fishermen to describe these flooding episodes and was formally accepted by UNESCO for scientific use in
• Swell waves occur when waves in a fully developed sea outrun the storm that creates them, traveling great distances from the wind source.
• These waves have lower frequencies compared to waves generated by local storms and are able to travel thousands of miles without significant changes in height and period.
• Swell waves organize into groups that appear smooth and regular in appearance.
• The longer the wave, the faster it travels, and as waves leave a storm area, they tend to sort themselves out with the longer ones ahead of the shorter ones.
• Further, the energy from swell waves is simultaneously spread out over an increasingly larger area as they travel.