Visiting glaciers is surely one of the highlights of a journey to Alaska. There are an estimated 100,000 glaciers in the State, covering three percent of the landscape and creating most of its rivers. Glaciers are rivers of ice that flow from ice packs high in the mountains, where more snow falls than melts. In constant motion, they can move ahead at speeds of several feet a day, or sudden surges of as much as 300 feet. Some are retreating, or shrinking due to increased melting or a lack of new snow to feed them.
Tidewater glaciers flow to the sea and are found at the head of fjords or inlets which they carved while retreating. Calving occurs when pieces of a tidewater glacier break off and fall into the sea. The creaking sounds associated with calving glaciers and the roar as pieces fall into the sea are as impressive as the visual scene. The beautiful blue color associated with glaciers is created by the density of the ice which absorbs all the colors of the spectrum except blue, which is reflected.