Terminal (End) Moraine, Alaska

In its steady state, a glacier is always carrying sediment to its snout and leaving it there, where it piles up like this in a terminal moraine or end moraine. Advancing glaciers push the end moraine further, perhaps smearing it out and running it over, but retreating glaciers leave the end moraine behind. In this picture, Nellie Juan Glacier in southern Alaska has retreated during the 20th century to the position at upper left, leaving a former terminal moraine at the right. For another example see my photo of the mouth of Lituya Bay, where an end moraine serves as a barrier to the sea. The Illinois State Geological Survey has an online publication on end moraines in the continental setting.