Scientists Track Down Source of Earth’s Hum

You can’t hear it, but the Earth is constantly humming. And some parts of the world sing louder than others.
After discovering the mysterious low-frequency buzz in 1998, scientists figured out that the Earth’s hum is caused not by earthquakes or atmospheric turbulence, but by ocean waves colliding with the seafloor. Now, researchers have pinpointed the source of the Earth’s “background noise,” and it looks like it’s coming primarily from the Pacific coast of North America.

Full article by Hadley Leggett on Wired