Алясканың Маргари мұзылдағы

Glacier in Glacier Bay, Alaska, United States

Margerie Glacier is a 21 mile (34 km) long tidewater glacier in Glacier Bay, Alaska, United States within the boundaries of Glacier Bay National Park and Preserve. The glacier begins on the southern slopes of Mount Root, elevation 12860 feet (3920 m), on the AlaskaCanada border flowing southeast down the valley, then turning to the northeast toward its terminus in Tarr Inlet. Margerie Glacier is one of the most active and frequently visited glaciers in Glacier Bay, which was declared a National Monument in 1925, a National Park and Preserve in 1980, a UNESCO World Biosphere Reserve in 1986 and a World Heritage Site in 1992. While most of the tidewater glaciers in the park have been receding over the last several decades, Margerie Glacier has become stable, neither growing nor receding, while Johns Hopkins Glacier is advancing. Margerie Glacier extends upstream for a length of 21 mile (34 km) from Tarr Inlet to its source on the southern slopes of Mount Root. In 1750, Glacier Bay was a massive single glacier but due to higher average temperatures and lower average snowfall amounts over the last several centuries it has been transformed into what is now a 65 mile (105 km) fjord with many smaller glaciers. Margerie Glacier is located at the extreme northwestern end of the bay and is situated perpendicular to the Grand Pacific Glacier.

Margerie Glacier is named after French geologist and geographer Emmanuel de Margerie who visited the area in 1913. When John Muir first visited the bay in 1879 the ice had retreated 48 mile (77 km) into the bay. The glaciers in Glacier Bay are remnants of a general ice advancethe Little Ice Agethat began about 4,000 years ago. This advance is not comparable to continental glaciation that occurred during the Wisconsin Ice Age of the Pleistocene epoch. About 1750, the Little Ice Age reached its maximum stage and a general recession of glaciers began. A tidewater glacier is one whose terminus encounters seawater at least at high tide, if not at all tide levels. Margerie Glacier and six other glaciers have termini that are fully submerged at all tide levels. Margerie Glacier has a total height of 350 feet (107 m) of which 250 feet (76 m) rises above the water level and 100 feet (30 m) is beneath the water surface. Freshwater upwellings emerge from the central area of the glacier's terminus, generated by meltwater streams running underneath the glacier. Such areas attract sea birds which feed on the fish that can be found there.

Margerie Glacier is a part of the Glacier Bay National Park and Preserve whichwith its combination of tidewater glaciers, coastlines, fjords, rivers and lakesprovides widely varying landscapes and seascapes that support 333 vascular plant taxa, 274 bird species, 160 fish species, 41 mammal species, and 3 amphibian species.