Central agencies have issued a red alert for ‘kallakkadal’, warning of sudden sea swells causing rough waves in coastal areas of Kerala and the south Tamil Nadu coast. 

This marks the first time a red alert has been issued for the phenomenon of ‘kallakkadal’ by the Indian National Centre for Ocean Information Services (INCOIS) and the National Disaster Management Authority (NDMA) in this part of the country.

What is ‘kallakkadal’?

• ‘Kallakkadal’ is the sudden swell of the seas causing rough waves. 

• INCOIS has said that the swells result from strong winds in the southern part of the Indian Ocean at certain times, and that they occur suddenly without any particular indications or warning. Hence the name ‘kallakkadal’.

• This phenomenon occurs mostly during pre-monsoon season and sometimes during post monsoon. It continues for a few days. It inundates the low lying coasts. 

• The INCOIS had said there is a possibility of rough seas due to high waves of 0.5 to 1.5 metres during this period.

• The officials have urged fishermen and coastal residents to take necessary precautions in response to the alert.

• There is a possibility of extremely strong waves, rough seas and sea incursion during this period. 

• The officials, however, said it was not a tsunami-like phenomenon.

What is the role of INCOIS?

• Indian National Centre for Ocean Information Services (INCOIS) was established as an autonomous body in 1999 under the ministry of earth sciences (MoES) and is a unit of the Earth System Science Organisation (ESSO).

• INCOIS is mandated to provide the best possible ocean information and advisory services to society, industry, government agencies and the scientific community through sustained ocean observations and constant improvements through systematic and focussed research. 

• INCOIS, being the central repository for marine data in the country, receives large oceanographic data in real time, from a variety of in-situ and remote sensing observing systems. 

• INCOIS has a prominent international presence, being a permanent member of the Indian delegation to Intergovernmental Oceanographic Commission (IOC) of UNESCO and a founding member of the Indian Ocean Global Ocean Observing System (IOGOOS).

Main functions of INCOIS:

• Provides round-the-clock monitoring and warning services for the coastal population on tsunamis, storm surges, high waves, etc through the in-house Indian Tsunami Early Warning Centre (ITEWC). The Intergovernmental Oceanographic Commission (IOC) of UNESCO designated ITEWC as a Regional Tsunami Service Provider (RTSP) to provide tsunami warnings to countries on the Indian Ocean Rim.

• Provides daily advisories to fisher folk to help them easily locate areas of abundant fish in the ocean while saving on both fuel and time used to search for the same. These advisories called ‘Potential Fishing Zone Advisories’ are issued in Hindi, English and eight vernacular languages. Currently more than one lakh fisher folk successfully use these advisories obtained through SMS, Village Information Centres, local radio, local TV, Electronic Display Boards at fish landing centres and NGO websites.

• Short term (3-7 days) Ocean State Forecasts (waves, currents, sea surface temperature, etc) are issued daily to fisher folk, the shipping industry, the oil and natural gas industry, the Navy, the Coast Guard, etc. These forecasts inform users about the expected sea conditions during the next few days and help them to plan their activities at sea.

• Deploys and maintains a suite of Ocean Observing Systems in the Indian Ocean to collect data on various oceanic parameters to understand the processes in the ocean and to predict their changes.

• Conducts systematic quality checks and archives all observational, satellite and other oceanic data at the ESSO-INCOIS Data Centre and then makes such data available to students, researchers and any other users. 

• ESSO-INCOIS has been designated as the National Oceanographic Data Centre by IOC/IODE of UNESCO and is also identified as the Regional Argo Data Centre for the Indian Ocean.

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