A moraine-dammed lake
occurs when a terminal moraine
has prevented some meltwater
from leaving the valley. Its most common shape is that of a long ribbon (ribbon lake
Example of moraine dammed lakes include:
- Argentina/Chile: Buenos Aires Lake
- Chile: Calafquén Lake, Panguipulli Lake
- New Zealand: Lake Hawea, Lake Ohau, Lake Pukaki, Lake Tekapo, Lake Wakatipu, and Lake Wanaka (i.e., almost all large lakes in the South Island)
- Switzerland: Lake Zurich
- United States: Donner Lake in California, Flathead Lake in Montana, Mille Lacs Lake in Minnesota, Wallowa Lake in Oregon
- Wales: Llyn Peris and its twin Llyn Padarn.
In the 19th century the Argentine explorer Francisco Perito Moreno proved that many Patagonian lakes draining to the Pacific where in fact part of the Atlantic basin but had been moraine dammed during the quaternary glaciations changing their outlets to the west. He Arguad that as originally belonging to the Atlantic basin these lakes should be awarded to Argentina.