Dynamics and paleoclimate history of ice sheets
During the past decades, the ice sheets of Greenland and Antarctica moved into the focus of public and scientific interest due to their sensitive response to global warming. Melting ice sheets would cause a significant sea-level rise which, in turn, would severely threaten low-lying coastal areas.
In order to better understand the dynamics of ice sheets, we need to study their development during the past millions of years. Data are still poor and under debate, especially for the early phase of ice sheet development. Short-term dynamics such as the oscillations during glacials and interglacials are much better known. We investigate mostly those areas that were once covered by ice sheets. In our studies, we combine a variety of data sets: geological samples, seismic and sediment echosounder profiles, and bathymetric data.
Only a sound understanding of the evolution of ice sheets will allow to generate reliable constraints for numerical simulations of a possible future behaviour of ice sheets.
In contrast to the continent Antarctica, the Arctic region consists of a large marine basin. Therefore, Arctic ice sheets are located on its surrounding land masses. At present, the only existing ice sheet is found on Greenland, but in the past, several other ice sheets covered large areas of the Arctic realm. The most important ones were the Laurentide Ice Sheet (North America), the Svalbard-Barents Sea Ice Sheet (on Svalbard and on the subaerially exposed Barents Sea) as well as the East Siberia-Chukchi Ice Sheet. During their maximum extent, these ice sheets reached far into the Arctic Ocean, and signs of glacial overprint can be found as far north as at the North Pole.
Many studies have shown that the onset of the Northern Hemisphere glaciation started some 2.8 million years ago, but many of the ice sheets likely have existed before. We study the initial phases of the ice sheets, their dynamics and history.
Laurentide Ice Sheet
Svalbard-Barents Sea Ice Sheet
East Siberia-Chukchi Ice Sheet
Little has been known about the long-term development especially of the WAIS, which as a marine based ice sheet generally reacts more sensitively to both atmospheric and oceanic warming than the largely terrestrial East Antarctic Ice Sheet (EAIS). The Antarctic Peninsula Ice Sheet (APIS) is widely regarded as sensitive to climate change due to its small size and northerly location, and because this region is one of the most rapidly warming places in the world. This sensitivity has been manifest through the collapse of numerous ice shelves, increased ice velocities, and the retreat and thinning of glaciers and ice caps.
Detailed geomorphological, geological, and geophysical studies are needed to gain insight into the initial formation and the dynamics of the ice sheets.
East Antarctic Ice Sheet EAIS
Jakobsson, M., L. A. Mayer, B. Coakley, J. A. Dowdeswell, S. Forbes, B. Fridman, H. Hodnesdal, R. Noormets, R. Pedersen, M. Rebesco, H.-W. Schenke, Y. Zarayskaya A, D. Accettella, A. Armstrong, R. M. Anderson, P. Bienhoff, A. Camerlenghi, I. Church, M. Edwards, J. V. Gardner, J. K. Hall, B. Hell, O. B. Hestvik, Y. Kristoffersen, C. Marcussen, R. Mohammad, D. Mosher, S. V. Nghiem, M. T. Pedrosa, P. G. Travaglini, and P. Weatherall, 2012. The International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 3.0, Geophysical Research Letters, doi: 10.1029/2012GL052219.
Arndt, J.E., H. W. Schenke, M. Jakobsson, F. Nitsche, G. Buys, B. Goleby, M. Rebesco, F. Bohoyo, J.K. Hong, J. Black, R. Greku, G. Udintsev, F. Barrios, W. Reynoso-Peralta, T. Morishita, R. Wigley, 2013. "The International Bathymetric Chart of the Southern Ocean (IBCSO) Version 1.0 - A new bathymetric compilation covering circum-Antarctic waters", Geophysical Research Letters, doi: 10.1002/grl.50413