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
August 29 along the coast, especially from Colachel in Kanyakumari district to
Kilakarai in Ramanathapuram district.
A spokesman 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
“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,” the spokesman said
said, adding that Tamil Nadu and Puducherry coasts would also witness gusty
winds reaching 45-55 kmph.
India is extending 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.
INCOIS is already providing these operational services to Maldives, Sri Lanka
“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.
India successfully deployed a wave rider buoy off Frigate Island,
Seychelles last year. 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.
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 meters above Maximum
Water Level (MWL).