An ice rise is a clearly defined elevation of the otherwise totally flat ice shelf, typically dome-shaped and rising 100 to 200 metres above the surrounding ice shelf. An ice rise forms where the ice shelf touches the rocky seabed because of an elevation in the seabed that remains below sea level. (In contrast, an elevation in the seabed that extends above sea level is defined as an island). The ice shelf flows over the seabed elevation, completely covering it with ice, thereby forming an ice rise. The resulting tension forms crevasses around the ice rise.