Uncharted Territory

Ultraslow ridges hold new clues to crust's formation

At the top of the world in the late summer of 2001, the U.S. Coast Guard’s icebreaker Healy carved a slow path through the ice-covered Arctic Ocean. On board, marine geologist Henry Dick sent dredge after dredge through the ice to the seafloor, searching for telltale rocks that would help shed light on how Earth’s crust forms.