By tracking the variations in the time it takes a 75 Hz tone (within the hearing range of many marine mammals) to travel from a sonar transmitter
in California to a receiver 6,000 miles away, the ATOC program can begin to plot the changes in ocean temperature over time.
Giles explains that the interoperability would make operating multi-static sonars easier to do: "The idea is that you could have sonar transmitters
in various locations, and then you can have receivers listening in other locations.
Working in the remote Kennedy River in North Queensland, Australia, Dr Hamish Campbell from University of Queensland and colleagues from Queensland Parks and Wildlife Service and Australia Zoo tagged 27 adult estuarine crocodiles with sonar transmitters
and used underwater receivers to track their every move over 12 months.