Tarr Inlet with Russell Island on the left, Glacier Bay National Park
So much going on in this photo one simply soaks in its beautiful composition. Ok, just another pretty picture, what is going on here. The foreground shows a complex area of recurved spit and salt marsh habitat intercepted by a spectacularly large alluvial fan. Both of these features are flanked by a glacially cut inlet. You can even see where the high tide was earlier in the day by the wet band of sediment across the fan and into the salt marsh. Despite this intersection of major geomorphic features, one is drawn to the background of this image wondering what lies around the corner, how far back does it go, could there be a glacier making its retreat? Well, it is called Glacier Bay National Park and Preserve!
Margerie Glacier, Glacier Bay National Park & Preserve.
Margerie Glacier is an icy highlight of any visit to Glacier Bay National Park, and a primary destination for visitors on sailboats, kayaks, tourboats, and cruise ships. It is about 1-mile wide, with an ice face that is about 250 feet high above the waterline, but with its base about 100 feet below sea level. The glacier is about 21 miles long and begins in snow-fields in the Fairweather Range where elevations exceed 9000 feet. The ice flows about 2000 feet per year, or about 6 feet per day. Margerie Glacier joined Grand Pacific Glacier about 1990, but they have since separated as Grand Pacific recedes.
Margerie Glacier is a hanging glacier with its base about 600 feet above the floor of Tarr Inlet near its center. As the flowing ice moves beyond the submerged valley floor, it breaks off and calves into the sea in spectacular fashion.
Margerie’s terminus was relatively stable in position through the 90’s; however, about 1998 the northern third of the terminus began a slight recession, forming a small embayment within the ice face.
Over the years, this part of the terminus has thinned and the embayment has expanded. In 2017, this section experienced dramatic changes with deep embayments and a large mass of bedrock now exposed. Perpetual meltwater discharges from subglacial streams below the water surface within the central area of the glacier resulting in upwellings and occasionally fountains. Where the ocean is disturbed by meltwater streams and calving icebergs, flocks of black-legged kittiwake gulls swarm and glean small marine creatures from the surface.
