Alaska PaleoGlacier Atlas: A Geospatial Compilation of Pleistocene Glacier Extents

Three decades after the last Alaska-wide compilations of glacial geology (Karlstrom et al., 1964; Coulter et al., 1965), we have coordinated a broadly collaborative effort to create a digital map of reconstructed Pleistocene glaciers. The Alaska PaleoGlacier Atlas is a geospatial summary of Pleistocene glaciation across Alaska. The layers in the atlas depict: 1) the extent of glaciers during the late Wisconsin glaciation (i.e. Last Glacial Maximum, about 20,000 years ago), and 2) the maximum extent reached during the last ca. 3 million years by the northwestern Cordilleran Ice Sheet, ice caps, and valley glaciers. The atlas is targeted for a scale of 1 to 1,000,000 -- suitable for visualization and regional analyses. Former glacier extents are based on decades of field-based mapping, air-photo interpretation, and a variety of dating methods. In all, the first version combines glacial-geologic information from 26 publications and 42 source maps. Revisions will be made and released as time and resources allow. A companion paper (Kaufman and Manley, subm.; part of an INQUA effort for a global atlas with regional reviews) summarizes the glacial-geologic evidence and highlights recent revisions, remaining uncertainties, and implications for paleoclimate forcing. See: "http://instaar.Colorado.EDU/QGISL/ak_paleoglacier_atlas/apg_overview.html"