This line shapefile contains cosmogenic exposure ages from late and early Wisconsinan drift linked to references in the geospatial database. Most 10Be and 26Al ages use the same or very similar production rate. All 36Cl ages use the same production rates. Refer to original reference for all details of age and scaling calculations, in addition to how authors handle erosion rate and snow shielding.This report is an update of the Alaska PalaeoGlacier Atlas. It includes information published since 2002 and is based on a more detailed map scale. In addition to the all-time maximum extent of former glaciers and the late Wisconsinan extent, this update includes the mapped limit for the penultimate glaciation, which generally occurred during the early Wisconsinan. The update also includes a compilation of cosmogenic exposure ages linked to the geospatial database. The Alaska PalaeoGlacier Atlas is a geospatial summary of Pleistocene glaciation across Alaska. Our goal is a comprehensive and consistent overview of former glacier limits across Alaska. Our hope is to facilitate outreach, education, and interdisciplinary research in the fields of geology, geography, biology, and natural history. Coastal boundary aligned with imagery, no gaps in polygon, no topological errors, aggregate and % figures verified This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
Creator:
World Data Center for Paleoclimatology and NOAA Paleoclimatology Program (U.S.)