The second major feature, a valley called Ithaca Chasma (named for the country ruled by Odysseus), runs roughly from the Tethyan north pole to its south pole. It is 62 miles wide, 2 to 3 miles deep, and extends 1,200 miles (100 kilometers, 3 to 5 kilometers, and 2,000 kilometers, respectively). Ithaca Chasma may have been caused by expansion of internal liquid water as it froze into ice after the surface had already frozen. An alternate theory is that the impact that created the Odysseus Crater also generated forces that created Ithaca Chasma, especially since the chasm is on the opposite side of Tethys from the Odysseus Crater. The chasm and surrounding area are heavily cratered, indicating that it was formed long ago.