Funds are provided in support of a RAPID award to study the dynamics of the tongue of Hubbard Glacier, Yakutat, Alaska. It is anticipated that the sustained advance of Hubbard Glacier?s tidewater terminus will soon create an ice dam at Gilbert Point, closing the tidal channel linking Disenchantment Bay with Russell Fiord and forming a 64 km long lake. The natural event has only rarely been observed and the creation of an ice dam by an advancing tidewater glacier represents an unparalleled opportunity to monitor the process. This study will document the anticipated formation of the ice dam and analyze the processes, mechanics and factors determining method and style of closure, dam stability and or failure. Understanding the dynamics of the ice margin is crucial to understanding how ice dams are created and their performance as a permanent closure to Russell Fiord. During the advance and closure, instrumental measurements coupled to sequential image analysis will examine the ice marginal marine environment in relation to monitored ice flow and ice structure at the dam site. Additionally, if a lake is formed behind the ice dam, the freshening evolution of the lake will be monitored.
