The same size as a small human diver can reach depths of 1,000 meters
Silent marine robots that record underwater sounds are allowing researchers at the University of East Anglia (UEA) to hear the oceans as never before.
The robots are about the same size as a small human diver but can reach depths of 1,000 meters and travel the ocean for months, covering thousands of kilometres. They communicate by satellite with their pilot to build an underwater sound landscape of the world’s oceans.
Pierre Cauchy, a doctoral researcher at the School of Environmental Sciences of the UEA, has been using one of these autonomous submarines for five years, recording submarine noises in the Mediterranean Sea and the North Atlantic and the Southern Ocean.
The recordings can be used to measure the wind speed on the sea surface and control storms, as well as eavesdrop on marine life.
Cauchy presented his research at the General Assembly of the European Union of Geosciences in Vienna. He showed how the robot, called Seaglider, can measure wind speed, listen to the sounds produced by fish and whales, and capture human activities, such as maritime traffic and seismic surveys.
By recording sounds in remote locations where there are no permanent weather stations, the robots provide valuable information about wind patterns or storms, which can help adjust the climate models.
Cauchy says that “as an acoustic, it is fascinating to listen to underwater life, like the long-finned pilot whales in the North Atlantic, but also to hear echoes of what is happening above.”
While pilot whales make whistles, buzzes and clicks, pods of hunting dolphins create sharp echolocation clicks and larger species, such as sperm whales, make stronger and slower clicks.
Strong winds raise the level of background noise, the intense pulses of seismic surveys are unique and easily identifiable, and marine vessels are clearly identified by low-frequency noise.
The Seaglider weighs just over 50 kilos and measures 1.5 meters in height. It is controlled remotely by a pilot and remains silent, so it only records the sound of the ocean without adding its own tones.
“Now that they have been shown to be useful in modelling climate, controlling storms or protecting marine life, I hope other researchers will integrate silent robot divers into their work and their use will be expanded,” Cauchy concludes.
Source: La Nueva Espana