Margerie Glacier - Features

Features

Margerie Glacier, categorized as a typical example of tide-water glacier (tidewater glacier is defined as a glacier which generates sufficient snow to flow out from the mountains to the sea.), has a total height of 350 feet (110 m), out of which 250 feet (76 m) raises above the water level and 100 feet (30 m) is beneath the water surface. (This height is stated to be larger than the 307 feet (94 m) high Statue of Liberty). The glacier exhibits a distinctive curved layer of rock debris mixed with ice. The glacier has impressive configurations (as if carved with hand tools), in a "jagged and twisted form", set in ice which is seen in blue color as a result of absorption of rays of shorter red and green wavelengths. It is a much cleaner glacier as compared to other glaciers in the Glacier Bay. It is also one of the most active glacier for "Calving" (a word meaning breaking and dropping of ice walls into the sea). As the glacier calves, "a rifle-like crack and a booming roar is heard creating a boiling like turbulence."

Some times, ice caves get formed in the glacier, which is considered highly unstable since blocks of ice collapse into the water from the sides of the cave formation and create a resounding noise as it splashes.

The glaciers in the Glacier Bay are stated to be remnants of a general "ice advance – the Little Ice Age – that began about 4,000 years ago". This advance is not comparable to continental glaciation that occurred during "Pleistocene times known as the Wisconsin Ice Age". However, about 1750, the 'Little Ice Age' reached its maximum stage and then melting started. Ice flows have been recorded at Margerie Glacier 2,000 feet (610 m) per year or 6 feet (1.8 m) per day. Its advance was reported to be at the rate of 30 feet (9.1 m) per year till 1998 when some degree of recession has been noticed at its northern terminus "forming a small embayment," while the southern part is advancing at 1 foot (0.30 m) per year. In the 1990s, the glacier was attached to the Grand Pacific Glacier. However, it is now detached from the Grand Pacific (which is said to be receding) and moranic material is seen where it has separated on its northern extremity, discerned by a small stream. As result, the Margerie Glacier is termed "a hanging glacier with its base about 600 feet (180 m) above the floor of Tarr Inlet near its center." Fresh water 'upswellings' are seen to emerge from the central area of the glacier, generated by the melt water discharges of sub glacial streams; such areas are swarmed by sea birds for feeding on fish.