Mass balance and ice dynamics of Antarctic Peninsula glaciers (MIT-AP)

Living Planet Fellowship research project carried out by Thorsten Seehaus.

Pronounced climatic changes have been observed at the Antarctic Peninsula within the past decades and its glaciers and ice caps have been identified as a significant contributor to global sea level rise. Dynamic thinning and speed-up was reported for various tidewater glaciers on the western Antarctic Peninsula. On the east coast, several ice shelves disintegrated since 1995. Consequently, former tributary glaciers showed increased flow velocities due to the missing buttressing, leading to substantial ice mass loss. Various studies were carried out to quantify the ice mass loss and ice discharge to the ocean at the Antarctic Peninsula using different approaches. However, the results are still subject to substantial uncertainties, in particular for the northern section of the Antarctic Peninsula (<70°S). Thus, the aim of this project is to carry out an enhanced analysis of glacier mass balances and ice dynamics throughout the Antarctic Peninsula (<70°S) using various remote sensing data, in-situ measurements and model output. By analyzing bistatic SAR satellite acquisitions, an unprecedented spatial coverage with surface elevation change information at the study area will be achieved to compute multi-temporal geodetic glacier mass balances on regional and glacier scales. Information on ice dynamics will be derived from multi-mission SAR acquisitions using offset tracking techniques. In combination with latest ice thickness data sets the spatiotemporal variability of the ice discharge to the ocean will be evaluated. By including information from in-situ measurements and model output of atmospheric and oceanic parameters, driving factors of the obtained change patterns will be assessed to enhance the understanding of the ongoing change processes. The project results will contribute fundamental information to international initiatives and institutions like IMBIE, IPCC and WGMS and address several “Advancing Earth System Science Challenges of the Living Planet”, defined by ESA.

Project outcomes:

“Within my LPF,I studied the glacier changes along the Antarctic Peninsula (north of 70°S), a hotspot of global warming, throughout the last ~30 years. I carried out the first regional assessment of ice volume and mass changes using the geodetic mass balance methods by means of repeat-pass TanDEM-X acquisitions. As compared to previous estimates using other approaches, I was able to significantly reduce the uncertainties in ice mass losses for this region, and providing ice thickness change information at unprecedented spatially detailed scales. Moreover, I investigate the changes of the ice flow to the ocean of >300 glaciers back to 1992 using mult-mission SAR remote sensing data. Compared to previous analysis a consistent ice thickness database and rigorous error analysis was employed. The combination of the ice discharge with regional climate modeling information indicated that the increase in ice discharge was widely balanced by more positive climatic mass balance. Both, the spatial patterns of ice thickness and ice dynamic changes can be related to ocean warming and climatic variations as well as to the previous brake-up events of ice shelves in the study region.”