Australian scientists claim that climate change can be predicted by sending sound waves underwater. When the water of the Indian Ocean is heated, the surrounding climate changes, affecting the monsoons, the Child's current, etc. Therefore, knowing the evolution of water temperature you can know if in the future there will be less or more rainfall in the environment.
The Australian CSIRO Marine Research sends sound waves from one point to another to follow the water temperature. Because the hotter the water, the faster these waves will move. Tests conducted in the Pacific Ocean with good results. Around the island of Cocos, signals and hydrophones are sent from 1,000 m deep, located in Diego Garcia, Crozet and Cabo Indio.
Comprehensive Nuclear Test Ban Treaty Organisation, which is responsible for detecting illegal nuclear tests, uses hydrophones from the general network to measure water temperature in thousands of kilometers.