Tidewater Glacier Velocities from Repeat Ground-Based Terrestrial LiDAR Scanning; Helheim Glacier, Southeast Greenland

Wednesday, 17 December 2014
David C Finnegan1, Gordon S Hamilton2, Leigh A Stearns3, Adam L LeWinter4, Hany Farid5 and Hanna Renedo2, (1)U.S. Army Cold Regions Research and Engineering Laboratory, Hanover, NH, United States, (2)University of Maine, Orono, ME, United States, (3)University of Kansas, Department of Geology, Lawrence, KS, United States, (4)US Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, NH, United States, (5)Dartmouth College, Computer Science, Hanover, NH, United States
Tidewater glaciers exhibit dynamic behaviors across a range of spatial and temporal scales, posing a challenge to both in situ and remote sensing observations. In situ measurements capture variability over very short time intervals, but with limited spatial coverage, and at significant cost and risk to deploy. Conversely, airborne and satellite remote sensing is capable of measuring changes over large spatial extents but at limited temporal resolution. Here we use a near-situ approach to observing dynamic glacier behavior. Terrestrial LiDAR Scanning (TLS) combines the rapid acquisition capabilities of in situ measurements with the broad spatial coverage of traditional remote sensing, and can be carried out from a safe off-ice location. Repeat (30 min) high-resolution, long-range (6-10km) TLS surveys were conducted at Helheim Glacier, southeast Greenland, during July 9-14, 2014, and coincident in situ global positioning system (GPS) observations were acquired close to the glacier terminus. Analysis of these data allows for independent estimates of flow displacement and verification of 3D analytic techniques for quantifying vector motion. These techniques will enable the automated processing of large volumes of repeat scanning data to be collected during planned the deployment of an autonomous version of our LiDAR scanning system.