TREE-RING DATING THE NEOGLACIAL ICE ADVANCE OF WACHUSETT INLET, GLACIER BAY NATIONAL PARK AND PRESERVE, SOUTHEAST ALASKA, USA

The retreat of glaciers coupled with high rates of uplift along the Gulf of Alaska has exposed new sequences of glacial deposits and datable materials for study. We focus our study on the trees overridden by the advancing Carroll Glacier at the head of Wachusett Inlet in upper Glacier Bay. Logs and stumps overridden and buried by Carroll Glacier were radiocarbon dated to ~3.2 to 3.6ka BP years, a time referred to as the Neoglacial when glaciers across the Gulf of Alaska were also advancing. From 49 of these logs, a floating ring width chronology will be developed and tested against a floating ring width chronology from Geikie Inlet to further refine the chronology of glacial activity in Glacier Bay during the Neoglacial. The next step in this project will be to compare our tree ring dates and chronologies from Wachusett and Geikie Inlets to multiple sites outside of Glacier Bay and examine the regional history of Neoglacial ice advance and retreat in the Gulf of Alaska region.