Reconstructions of mountain glacier profiles, northeastern United States

Ice surface profiles are reconstructed for 37 proposed mountain glacier localities in the northeastern United States, including sites in the Catskill and Adirondack Mountains, New York; the Green Mountains, Vermont; the White Mountains, New Hampshire; and the Longfellow Mountains and Mount Katahdin, Maine. The reconstructions, determined numerically from the shear-stress equation Psi = rho gh sin alpha , show estimated ice thickness as a function of valley position and slope. In general, ice thickness increases from zero at the position of the glacier terminus (terminal position is a required input to the model) to some equilibrium "slab" thickness in the upper valley, where the slab thickness is inversely proportional to valley slope.Glacier reconstructions support the empirical evidence for former local glaciation in the Catskill and White Mountains and in some localities in the Adirondack Mountains. In several proposed glacier locations in the Adirondack and Green Mountains (in very shallow basins and in very gently sloping valleys), however, estimated ice thicknesses exceed the depth of their respective valleys or the elevation of up-valley cols, suggesting a re-evaluation of these localities as sites of local confined ice flow. Confirmed localities of local glaciation are mostly in valleys with mean gradients greater than about 5 degrees where reconstructed ice thicknesses are less than about 200 m.