Historical Structure From Motion (HSfM): Automated Generation of High-Resolution DEMs and Geodetic Glacier Mass-Balance Measurements from Historical Aerial Photography

Abstract:

Mountain glaciers are responding in concert to a warming global climate over the past century. However, on interannual to decadal time scales, individual glaciers show patterns of both retreat and advance, as a function of regional climate forcing, local geometry, and internal dynamics. To better understand glacial responses at higher temporal and spatial resolution, we augment traditional glacier mass-balance records with geodetic measurements derived from scanned historical aerial photography archives, including the USGS North American Glacier Aerial Photography (NAGAP) and EarthExplorer Aerial Photography Single Frame collections.

Our automated photogrammetry workflow (HSfM) produces accurately georeferenced, sub-meter resolution Digital Elevation Models (DEMs) and orthoimage mosaics, without manual Ground Control Point (GCP) selection. Here, we present initial results of interannual to decadal geodetic mass-balance measurements from the 1960s to 2010s for a sample of glaciers across the Western United States. By improving the long-term record and temporal resolution of glacier mass-balance measurements made at a regional scale, we hope to inform hydrologic model predictions and management decisions affecting downstream water resources and geohazard risk.