Deep sea ears to hear N-blasts

An underwater listening device used for detecting nuclear explosions will be sunk off Cape Leeuwin next year.

The device will also revolutionise research into global warming and climate change.

The underwater microphone is one of three which will be sunk in deep water in the Indian Ocean as part of a global network for discouraging secret nuclear tests.

The microphones or hydrophones, to be installed by the Vienna based Comprehensive Nuclear Test Ban Treaty Organisation (CNTBTO), will also be placed off British territory in the northern Indian Ocean and near the French sub-Antarctic island of Crozet.

The French research ship Marion Dufresne returned to Fremantle on Tuesday after a six day trip to survey the Cape Leeuwin site.

Researchers from the CSIRO's marine research section, Curtin University's Centre for Marine Science and Technology and WA based company Fugro Survey Pty Ltd took part in the survey.

CSIRO oceanographer Andrew Forbes said an Australian-United States-led project would also use the devices to monitor ocean temperature changes.

Dr Forbes said the hydrophones detected all underwater sounds and scientists could discern between natural sounds and man-made sounds.

The Indian Ocean climate project would set up a separate speaker in the ocean to transmit signals and then measure how long it took for the signals to reach the CNTBTO microphones.

By measuring the travel time of the signals it was possible to determine water temperature.

Dr Forbes said the project would generate information beyond the realm of established oceanographic research techniques.

It would provide a better understanding of regional influences on Australian rainfall, which had strong links to Indian Ocean temperatures.

[Courtesy: The West Australian]