Story: Glaciers and glaciation

Throughout the 20th century the Tasman Glacier has gradually melted and thinned, and its surface has become covered in moraine (rock, sand and clay carried by the glacier). Tasman Lake began to form on the lowest section of the glacier in the mid-1980s, and has gradually grown, with icebergs floating on the surface. Water flows out of the lake into the Tasman River, and from there into Lake Pūkaki.