A heavily crevassed glacier, about 45 mi long and averaging 20 mi wide. It reaches the sea between Cape De la Motte and Cape Hurley where it continues as a large glacier tongue. Discovered by the AAE (1911-14) under Douglas Mawson, who named it for Xavier Mertz, a member of the expedition who lost his life, Jan. 7, 1913, on the far-east sledge journey.