CHENNAI: The Indian National Centre for Ocean Information Services (INCOIS), which functions under the Ministry of Earth Sciences, has issued a high wave warning to southern Tamil Nadu, eight other States and two Union Territories.
Monstrous waves measuring 3 to 3.5 metres are forecast till 11.30 pm on Tuesday along the coast, especially from Colachel in Kanyakumari district to Kilakarai in Ramanathapuram district.
Speaking to Express, Balakrishnan Nair, head of INCOIS, said these high-energy swell waves will hit the shore at a speed of 52-60 cm/sec.
The recent devastation caused in North Chennai, from Chinna Kuppam to Kosasthalaiyar, was also due to this phenomenon called Kallakkadal. During this period, the waves rise without warning and pose a potential risk to coastal communities.
“We have passed on the information to the disaster management cells of the respective states, Union Territories and fishermen communities. Besides Tamil Nadu, warning has been issued to specific pockets in Andhra Pradesh, West Bengal, Odisha, Karnataka, Maharashtra, Kerala, Gujarat, Goa, Lakshadweep, Andaman and Nicobar,” he said, adding that Tamil Nadu and Puducherry coasts would also witness gusty winds reaching 45-55 kmph.
Meanwhile, India has extended its expertise in ocean forecasting and early warning system for Comoros, Madagascar, and Mozambique as part of the Regional Integrated Multi-Hazard Early Warning System for Asia and Africa (RIMES) initiative.
M Rajeevan, secretary, Ministry of Earth Sciences, Government of India, and chair, RIMES Council, launched the system for operational use in the presence of David Grimms, president of the World Meteorological Organization (WMO) in Port Moresby, Papua New Guinea. INCOIS is already providing these operational services to Maldives, Sri Lanka and Seychelles.
“India is currently the leader in ocean forecast and early warning system in the Indian ocean region. We are looking to increase the number of buoys and other ground infrastructure to receive more data and improve forecasting. Last year, we successfully deployed a wave rider buoy off Frigate Island, Seychelles. Similar buoys have been planned for Sri Lanka and other network countries in Indian ocean region. Tsunami waves and other unprecedented sea changes first hit these countries before reaching the Indian coast,” Nair said.
For instance, wave surge and coastal flooding incidents that occurred between July 28 and August 3 last year along Kerala and West Bengal were well-predicted. Real-time data from Seychelles was highly beneficial for predicting these incidents, as many of these remotely forced waves originate from the southern and western Indian Ocean, he added.
The ‘sea thief’
Kallakkadal (Sea Thief), in fishermen’s parlance, is used to describe the phenomenon where sea water creeps in like a thief arriving unannounced
Sea creeps into coast because of swells generated by storms elsewhere. Travelling thousands of kilometres across entire ocean basins, the swell becomes amplified when it encounters a coastal current, resulting in high waves
In Tamil Nadu, Kallakkadal usually occurs during the pre-monsoon period and sometimes during post-monsoon months .
It continues for a few days and inundates the low lying coasts.
During high tide, water level can reach as much as 3-4 m above Maximum Water Level (MWL).