Glacier Terminus Estimation from Landsat Image Intensity Profiles

Mountain glacier retreat is an important problem related to temperature increase caused by global climate change. The retreat of mountain glaciers has been studied from the ground, but there exists a need for automated methods to catalog glacial change with a wider scope. A viable approach is to extract intensity profiles from Landsat images along the glacial flowline and follow the terminus location over time. We propose a new robust and accurate statistical algorithm to estimate the movement of glacial termini over time from these extracted image intensity profiles. Themethodweproposefirst uses regression splines to smooth the image intensity profiles. For each profile, the glacial terminus location is assumed to lie near a point of high negative change in the smoothed profiles. An approximate path of termini locations over time is obtained by an algorithm that seeks to minimize the cumulative first derivative value across the profiles. Spline smoothing is applied to this pilot path for estimation of long-term terminusmovement. The predictions from the method are evaluated on simulated data and compared to available ground measurements for the Nigardsbreen, Gorner, Rhone, and Franz Josef glaciers.