Holocene deglaciation in Adelie Land from 10Be cosmogenic dating

The question of current sea-level upraise related to Antarctica ice cap dynamics is crucial. In this context, paleo-proxy records and long-term observational datasets are an underused resource in terms of strategies for improving Antarctic climate projections for the 21st century and beyond. However our knowledge on the evolution of glacier changes in the West Antarctic ice Sheet (WAIS) and in the EAIS remains limited. A synthesis of cosmic ray exposure (CRE) dating applied in Antarctica from the ICE-G database reveals several issues in the spatial and temporal distribution. Based on this summary, it is still difficult to document the millennium scale glaciers evolution during the Holocene.

In this innovative project, we plan to explore two major questions. First we will document the millennium scale evolution of glaciers in Adelie Land and explore the possible influence of oceanic and atmospheric temperature changes based on already available transient climate simulations. This study will be based on 10Be CRE ages from nunataks and moraine remains near DDU. The establishment of this chronology needs to be acquired at the beginning of the project. About 50 samples will be prepared at CEREGE laboratory and measurements will be performed at the national facility ASTER, the 5MV Accelerator Mass Spectrometer (AMS), (CEREGE, Aix-en-Provence). Second, this Adelie Land chronology will be compared with a comprehensive review of Holocene glacier chronologies in Antarctica realized during this project in order to underline possible differences or synchronies between Adelie Land and other regions of the East Antarctic ice sheet and the other sectors of Antarctica.

The requested duration of this project is of which is 4 years, and is based on collaborations established for several years. It will be directed by V. Jomelli DR2 Cerege, assisted by Y. Rolland (Edytem) and R. Braucher CRCN Cerege who will be in charge of the field sampling and the cosmogenic dating. External collaborations are developed with the IGE for the glaciological aspects and with EPOC and the University of Sydney (CCRC) for the climatic modeling aspects which have been efficient for the last couple of years.