Terminal moraine

Terminal moraine

The Salpausselkä terminal moraines in Southern Finland
The Marseilles terminal moraine located southwest of Chicago

A terminal moraine, also called end moraine, is a moraine that forms at the snout of a glacier, marking its maximum advance.

Terminal moraines are one of the most prominent types of moraines in the Arctic. One famous terminal moraine is the Giant's Wall in Norway which, according to legend, was built by giants to keep intruders out of their realm. It is now known that terminal moraines are created at the edge of the greatest extent of the glacier. At this point, the debris that has been accumulated by plucking and abrasion, that has been pushed by the front edge of the ice is driven no farther, but instead is dumped in a heap. Because the glacier acts very much like a conveyor belt, the longer it stays in one place, the greater the amount of material that will be deposited. The moraine is left as the marking point of the terminal extent of the ice.

In North America, the Outer Lands is a name given to the terminal moraine archipelago of the northeastern region of the United States (Cape Cod, Martha's Vineyard, Nantucket, Block Island and Long Island). Other prominent examples of terminal moraines are the Tinley Moraine and the Valparaiso Moraine, perhaps the best examples of terminal moraines in North America. These moraines are most clearly seen southwest of Chicago.

In Europe, virtually all the terrain in the central Netherlands is made up of an extended terminal moraine. In Switzerland, alpine terminal moraines can be found, one striking example being the moraine at the end of the valley of the Forno Glacier in the south-eastern canton of Graubünden near St. Moritz and the Italian border.

In New Zealand the Franz Josef Glacier on the West Coast has created the terminal moraine called the Waiho Loop.

"The Mothership", a 3-mile wide terminal lobe of a glacier flowing down from the interior ice cap on top of the Byam Martin Mountains, Bylot Island, Nunavut. Note the dramatic terminal moraine "bulldozed" at the ice front.

See also