Geophysics has shown that precise measurements and a little modeling can perform wonders, like showing us the detailed structure of the Earth’s interior despite the fact that it is inaccessibly buried beneath hundreds of kilometers of rock. This is possible because seismic waves produced by earthquakes subtly change velocity or direction as they pass through different materials. A new paper shows that something similar can actually measure small temperature changes in the deep ocean.
An idea to use acoustic waves from man-made sources was actually floated several decades ago but died out after some trials. A team led by Wenbo Wu at the University of Toronto realized that earthquakes could be taken advantage of in the same way, removing the expensive logistics of constantly setting off booms to get