We present interannual to decadal glacier and geomorphic change measurements at multiple sites across Western North America from the 1950s until present. Glacierized study sites differ in terms of glacial geometry and climatology, from continental mountains (e.g., Glacier National Park) to maritime stratovolcanoes (e.g., Mt. Rainier). Quantitative measurements of glacier and land surface change are obtained using the Historical Structure from Motion (HSfM) package. The automated HSfM processing pipeline can derive high-resolution (0.5-2.0 m) Digital Elevation Models (DEMs) and orthomosaics from historical aerial photography, without manual ground control point selection. All DEMs are co-registered to modern airborne lidar and commercial satellite stereo reference DEMs to accurately measure geodetic surface elevation change and uncertainty. We use scanned historical images from the USGS North American Glacier Aerial Photography (NAGAP) archive and other aerial photography campaigns from the USGS EROS Aerial Photo Single Frames archive. We examine the impact of regional climate forcing on glacier volume change and dynamics using downscaled climate reanalysis products. By augmenting the record of quantitative glacier change measurements and better understanding the relationship between climate forcing and heterogeneous glacier response patterns, we aim to improve our understanding of regional glacier mass change, as well as inform management decisions impacting downstream water resources, ecosystem management, and geohazard risks.

We are developing a fully automated Structure from Motion (SfM) processing pipeline to generate high-resolution digital elevation models (DEMs) from archives of historical aerial and satellite imagery acquired between the 1950s to the 1990s. Scanned images are loaded directly from online archives and processed using open-source software deployed on cloud-computing infrastructure. Modern DEMs with high resolution and accuracy (e.g., airborne lidar, stereo DEMs from sub-meter satellite imagery) are used to iteratively improve historical image geolocation, without manual processing steps involving ground control. We present preliminary DEM and orthoimage time series for glaciers in Washington state, derived from the USGS North American Glacier Aerial Photography (NAGAP) archive. These records document surface elevation change with sub-meter vertical accuracy over decadal timescales. We are using these observations to quantify evolving rates of glacier mass change and proglacial sediment transport. Our aim is to generate long-term, regional records of glacial response to climate forcing on decadal timescales. Better understanding these past responses will help constrain projections of future glacier change under different climate scenarios, as well as impacts on downstream water resources.