The zone separates the Juan de Fuca and North America plates, and as a new ocean floor is being created, ocean material wells
up and moves toward the coasts of Washington and Oregon.
Midocean ridges are seams where material wells
up from Earth's interior to form new seafloor, explains Hedy Edmonds, a marine geochemist at the University of Texas' Marine Science Institute in Port Aransas.
The icy crust of Europa, Jupiter's enigmatic moon, bears many sharp, fresh-looking dark and gray bands that probably formed when material welled
up from a warmer icy slush below.