Landslide mapping to support hazard assessments in Glacier Bay National Park and Preserve, Alaska
Landslides that displace water, whether they initiate underwater or on land, have the potential to cause tsunami waves that can pose a significant risk to marine activities and coastal infrastructure.
Populated sheltered inlets and narrow bays can be particularly vulnerable, and the effects of water displacement from moving sediment can be amplified as compared to the effects from similarly sized mass movements in open water. In deglaciating landscapes, such as the fjords and mountain slopes adjacent to tidewater glaciers found in Southeast Alaska, glacial retreat and permafrost decay can destabilize rock slopes and increase landslide potential. Establishing and maintaining inventories of subaerial and submarine landslides in such environments is critical for identifying the magnitude and frequency of past events, as well as for assessing areas that may be susceptible to slope failures caused by deglaciation or triggered by earthquakes in the future. This data release provides an inventory of submarine and subaerial-to-submarine landslide features in Glacier Bay, Glacier Bay National Park and Preserve, Alaska. Mapped features are intended to inform landslide susceptibility mapping in Glacier Bay by providing a qualitative baseline of landslide activity prior to 2009 when the most recent bathymetric data were collected. Data include GIS polygons delineating landslide source and deposit areas; polylines delineating probable landslide scarps with no visible deposits; a composite bathymetric elevation raster; a slope raster; and a topographic openness map that was used to map features. This work was supported by funding through the Additional Supplemental Appropriations for Disaster Relief Act of 2019 (H.R. 2157).