Waves in the deep
Acoustic-gravity waves — a special type of sound wave that can cut through the deep ocean at the speed of sound — can be generated by underwater earthquakes, explosions, and landslides, as well as by surface waves and meteorites. A single one of these waves can stretch tens or hundreds of kilometers, and travel at depths of hundreds or thousands of meters below the ocean surface, transferring energy from the upper surface to the seafloor, and across the oceans. Acoustic-gravity waves often precede a tsunami or rogue wave — either of which can be devastating. Now a new study by an MIT researcher suggests that these immense deep-ocean waves can rapidly transport millions of cubic meters of water, carrying salts, carbons, and other nutrients around the globe in a matter of hours. Usama Kadri, a postdoc in MIT’s Department of Mechanical Engineering, tracked the theoretical movement of fluid caught up in an...