Title

Hydrologic processes at Bering Glacier, Alaska

Document Type

Article

Publication Date

2010

Abstract

Runoff from the mountains and large glaciers on the rim of the Gulf of Alaska is a critical driver for ocean circulation in the gulf and a major contributor to global sea level rise. Bering Glacier is the foremost glacier of this system, with one of the largest proglacial lake-river systems in the world, Vitus Lake, which is linked to the Gulf of Alaska by the Seal River. Vitus Lake, at sea level and >250 m deep in some locations, receives all of the runoff, rainfall, and glacial melt from the Bering Lobe, which then flows into the Gulf of Alaska in the 8-km-long Seal River. Six years of conductivity-temperature-depth (CTD) surveys in Vitus Lake show a highly stratified system with 50% diluted seawater at the bottom. The annual surveys show changes in the deep water temperature and salinity that are the result of seawater intrusions. To understand the complex interaction between lake level and area, glacier discharge, river morphology and flow, sea level fluctuations, and their associated impacts on the lacustrine ecology of Vitus Lake, we developed a hydrodynamic flow model that was calibrated using field measurements of lake level and the flow in Seal River. The model is used to analyze present conditions in Vitus Lake and shows that even with no runoff entering the lake, the distance from the Gulf of Alaska through Seal River to Vitus Lake is too great for typical tidal inflow to reach the lake. Furthermore, the model is used to understand the response of the glacier-lake system to possible future scenarios of glacier retreat or advance and changes in runoff. Finally, properly calibrated, such a model would be able to gauge the discharge from the Bering Glacier System by measuring only the lake level.

Publisher's Statement

© 2010 Geological Society of America. Publisher's version of record: http://specialpapers.gsapubs.org/content/462/105.abstract

Edited by: Robert A. Shuchman Michigan Tech Research Institute Edward G. Josberger U.S. Geological Survey

Publication Title

GSA Special Papers 462, Bering Glacier: Interdisciplinary Studies of Earth's Largest Temperate Surging Glacier