Seasonal and multi-year surface velocity oscillations in North West Svalbard glaciers
Damien Mansell(1) and Adrian Luckman(2)
(1) Swansea University, School of the Environment & Society, Swansea, SA2 8PP, United Kingdom
(2) Swansea University, School of Environment & Society, Swansea SA2 8PP, United Kingdom
Calving of icebergs is a significant mass loss component for polar ice sheets and glaciers. The calving flux depends on terminus thickness and flow rates, which in turn may potentially be influenced by both surface and fjord processes.
In this study the highly variable flow rates of glaciers in North West Svalbard are investigated along with the important processes and factors that control calving. SAR images from JAXA Advanced land observing satellite and ESA European Remote Sensing Satellite are utilised to construct surface velocities and glacier terminus positions. Feature tracking between paired SAR scenes provides surface velocity in both the slant-range and azimuth directions. In this study feature tracking techniques are optimised for ALOS PALSAR paired scenes providing surface velocity data over the 46 day satellite repeat cycle. Tracking techniques developed fro ERS and Envisat images are modified to account for the different pixel spacing and resolution of the ALOS SAR images. Seasonal oscillations and multi-year fluctuations in surface velocity are monitored over the velocity time series in excess of 10 years. The processes which control terminus velocity fluctuations are investigated to better understand the complex coupled calving processes controlling the timing and magnitude of ice loss in Arctic ice masses.