C53C-0794
What Can We Learn About Glaciers and Ice Sheets From 30 Years of Landsat Imagery?
Friday, 18 December 2015
Poster Hall (Moscone South)
Alex S Gardner, NASA Jet Propulsion Laboratory, Pasadena, CA, United States, Ted Scambos, National Snow and Ice Data Center, Boulder, CO, United States and Mark A Fahnestock, University of Alaska Fairbanks, Fairbanks, AK, United States
Abstract:
Glacier and ice sheets are known to be rapidly changing and currently account for two thirds of observed sea level rise. Attributing the causes of the rapid decline in land ice requires separation of mass change processes, i.e. accumulation of precipitation, meltwater runoff, and solid ice discharge. Here we examine a 30 year record of Landsat imagery to determine trends in glacier velocity at a global scale in an attempt to identify anomalies in glacier flow that are contributing to changes in land ice mass. The Landsat archive represents a treasure trove of information with hundreds of thousands of images acquired over glaciers and ice sheets during the past 30 years. Gleaning useful and consistent surface displacement information from a multiple sensor archive that is heavily contaminated by cloud, saturated images, poorly resolved sensor geometry, and data gaps has proved challenging. Temporal stacking of displacement fields (Dehecq et al., 2015) and correcting for unresolved topography (Roseanau et al., 2012) have been shown to greatly improve derived velocities. Here we present results from a global processing of the complete Landsat archive for information on glacier surface displacements. We highlight patterns of coherent regional change as well as well as rapid basin-scale changes in glacier flow.
