PRELIMINARY LANDSLIDE INVENTORY OF PARTS OF THE FAIRBANKS NORTH STAR BOROUGH, ALASKA.

Landslides are geologic hazards that threaten human lives, property, and infrastructure. Effective landslide threat mitigation requires identifying, inventorying, and studying landslides; developing a detailed landslide inventory map is the beginning of this process. Here we present the first landslide inventory map of parts of the Fairbanks North Star Borough (FNSB), Alaska, along with supporting data and a qualitative analysis of the results. This research was funded by the U.S. Geological Survey (USGS) EDMAP program, which funds universities to train the next generation of geologic mappers. The map and geodatabase were developed using lidar-derived elevation data and satellite imagery, and supplemented with data from targeted fieldwork, which included field verification of landslides and a detailed field survey and series of laboratory soil tests on the large, informally named Tanana 440 landslide. We identified 1,679 landslides within the FNSB region, with 681 mapped within the focused EDMAP study area. These landslides occurred in bedrock and surficial loess deposits and vary widely in age, morphology, and material type. Most are prehistoric, but we did observe some historic and active landslides. Potential landslide triggers may include thawing permafrost, rain events, seismic events, and river erosion. Our goals with this work are to increase awareness of landslides as a potential geohazard and to aid state and local agencies and the general public in making informed land management decisions. [ABSTRACT FROM AUTHOR]