Something was nagging at William Hawley, and it was more about what was missing than what was there.

As a Ph.D. student at the University of California, Berkeley, Hawley is fascinated with the geologic complexities of the Cascadia subduction zone, a giant fault off the coast of the Pacific Northwest. There, the Juan de Fuca tectonic plate plunges under the North American plate, building strain throughout the region and prompting fears of the massive earthquake that could strike when it releases.

Hawley, however, was distracted by a peculiar region below central Oregon where it appears that a chunk of the Juan de Fuca plate is missing. He wasn’t the first to notice this gap, but it nagged at the