CHENNAI: Researchers at city-based National Institute of Ocean Technology (NIOT) have designed and tested an underwater tsunami buoy as an alternative to the existing surface buoys that are often damaged by man and nature.
The new buoy called Continuously Homing Submerged Autonomous Tsunami Underwater System (CHATUR) lies silent at 300m depth in the water and pops up to the surface only when its sensors detect abnormal water pressure on the seafloor. The buoy have been undergoing tests in the Bay of Bengal and the Arabian Sea since December 2019 and researchers are now ready for technology transfer.
R Venkatesan, head of Ocean Observation Systems, NIOT, said the new system transmits data only when the sensors detect an unusual change in water pressure. “We have completed testing of the prototype. We will soon transfer the technology to industry. We will deploy it in the oceans in addition to the existing systems,” he said.
At present, India has tsunami buoys at strategic locations close to the Andaman-Sumatra subduction fault in the Bay of Bengal and Makran fault in the Arabian Sea. They collect data and transmit on a daily basis to the Indian Tsunami Early Warning Centre in INCOIS, Hyderabad, and mission control centre at NIOT through INMARSAT.
Chatur has four main subsystems — bottom pressure recorder, extendable buoy system, motorised winch and brake system, and position mooring with acoustic release mechanism. Researchers said Chatur activates when it measures abnormal pressure associated with change in the height of the water column. The sensor sends out an acoustic message to the transceiver in the extendable buoy system, lying dormant at 300m, which then signals the winch to lift the buoy to the sea surface. The buoy then transmits the data through satellite to the servers on land. Once the pressure returns to normal, the winch pulls the buoy back to its original position underwater.
Researchers said this operation of the buoy only on demand reduces acts of vandalism and reduces the mooring load because of relatively lower subsurface water currents. The instruments suffer less biofouling and hence reduced maintenance and the low ambient temperatures underwater also protects the life of the electronic systems, hence making them fit for many other strategic applications.
In all, 31 buoy vandalism events were reported in the Indian Ocean during 2006-2010.