Til bevillingsoversigt

Reconstructing ice dynamics in Dronning Maud Land, East Antarctica (RIDDLE)

Carlsbergfondets internationaliseringsstipendier

What

Ice masses on Earth are undergoing major changes. However, to relate these changes to a long-term climate perspective we rely on the geological record. Past volume changes of the East Antarctic Ice Sheet have been assessed through marine records, yet, a relatively untapped terrestrial source of information exists on ice-free mountains (nunataks) protruding the ice sheet. In this project, I will reconstruct past ice-sheet dynamics in the Dronning Maud Land sector of East Antarctica by developing new methods to date the exposure age of rocks at the surface.

Why

The East Antarctic Ice Sheet is the largest ice sheet on Earth holding water corresponding to 58 m of sea-level equivalent. Although total collapse of the ice sheet is unlikely in the near future, even modest volume changes can have a significant impact on global sea level. By reconstructing past ice-sheet configurations we can improve our understanding of the complex links between climate, topography and ice in Antarctica. This project aims at providing a dataset to test and improve ice-sheet models, ultimately leading to better future ice-volume and sea-level change predictions.

How

To constrain the timing of past ice-sheet changes, I will analyse rare isotopes created by interaction with cosmic radiation in rock samples collected from nunataks in Dronning Maud Land. Cosmogenic analyses are routinely done in quartz minerals, however, key areas in Dronning Maud Land lack quartz-bearing rocks. I will therefore develop the cosmogenic method in feldspar minerals that are more abundant at the Earth's surface. Furthermore, by analysing multiple cosmogenic isotopes, I will constrain potentially complex exposure- and burial histories.

SSR

This project has the potential to expand our knowledge of the sensitivity of the East Antarctic Ice sheet by providing a dataset to test and improve ice-sheet models. Such information is key in order to constrain future changes of the ice sheet in a warming climate. Improved sea-level change predictions can aid society to establish better socio-economic adaptation schemes. Furthermore, methodological development of the cosmogenic method in feldspar minerals will be useful in other quartz-poor regions of the Earth.