UNIVERSITY OF ALASKA AND 2000 KECK CONSORTIUM UNDERGRADUATES CONTRIBUTE DATA TO FIELD STUDIES OF THE MENDENHALL GLACIER WATERSHED JUNEAU, ALASKA, 1998 TO PRESENT

Beginning in 1998, undergraduates participated in a variety of research programs centered on the Mendenhall Glacier and Mendenhall Valley watershed in Juneau, Alaska. Student participation was funded through grants to the UAS Environmental Science Program (UA Natural Resources Fund with local helicopter company support), the UAF-Geophysical Institute (NSF REU Program), and the 2000 KECK Consortium Geology program. Undergraduates either assisted faculty or performed faculty-directed research on their own initiative. Areas of research included glacier mass balance studies, GPS surveys of glacier motion and terminus retreat, radio echo sounding to measure glacier thickness, bathymetric surveys of proglacial Mendenhall Lake, analysis of suspended sediment in watershed streams, investigation of changes in valley hydrology and geomorphology as a result of glacier thinning and terminus retreat, and radiocarbon dating of subfossil tree stumps and peat layers. This work has helped to quantify a 100-m calving retreat in Mendenhall Lake during the 1999-2000 and the overall loss of 5.5 km2 of ice since 1948 and created datasets that enabled the construction of an updated bathymetric map in 2000. The map documented a lake area expansion of 4.6 x 106m2 and 6.9 x 106m3 in volume since 1973. Glacier sediment accumulation and erosion volumes are being estimated from this comparison. This bathymetric data in combination with turbidity measurements and ongoing suspended sediment flux studies, is being used to help establish annual glacier erosion rates and quantify the contribution of meltwater to the Mendenhall River and valley groundwater systems.