TAG: GS-1: GEOGRAPHY
THE CONTEXT: Hyderabad-based Indian National Centre for Ocean Information Services (INCOIS) has issued a broad advisory regarding high sea waves over parts of Srinivasapuram, Chennai coastal areas.
EXPLANATION:
About Swell Waves:
- A swell is the formation of long wavelength waves on the surface of the seas. These are composed of a series of surface gravity waves.
- Swell waves organise themselves into groups of similar heights and periods, and then travel long distances without much change.
Formation of Swell Waves:
- Generation: Swells begin as wind waves, which are generated by the wind blowing over the surface of the ocean. The energy transferred from the wind to the water creates waves.
- Their wavelengths may rarely exceed more than 150 m. Swell wavelength, also, varies from event to event. Occasionally, swells which are longer than 700 m occur as a result of the most severe storms.
- Growth: These waves can grow larger if the wind continues to blow steadily over a long distance (fetch) and a sufficient period.
- It occurs without precursors or any kind of local wind activity and as a result.
- Propagation: Once the waves move out of the area influenced by the generating wind, they start to organize into sets of smoother, more uniform waves. The process of dispersion helps in sorting the waves according to their speed and wavelength, with longer waves moving faster and outpacing the shorter ones.
- Swell: The remaining organized, long-period waves that have travelled out of their generating area are known as swell waves. They can travel across entire ocean basins from their source to distant shores.
Impact of Swell Waves:
- Surfing: Swells are essential for surfing, providing the consistent, large waves sought after by surfers. The quality of surf breaks is significantly influenced by the characteristics of incoming swells, such as their direction, period, and size.
- Coastal Erosion: Swell waves can contribute to coastal erosion, especially during storms when their energy is amplified.
- Navigation and Safety: For maritime navigation, understanding swells is crucial for the safety and efficiency of shipping and small craft operations.
- Energy Generation: Swell waves are a focus of research for renewable energy generation, where their consistent nature could be harnessed to produce electricity.
In India early warning systems like the Swell Surge Forecast System launched by the Indian National Centre for Ocean Information Services (INCOIS) in 2020 gives forewarning seven days in advance.
Swell waves vs Wind waves
| Wind Waves | Swell Waves |
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