Internal structure of the ice sheet between Kohnen Station and Dome Fuji revealed by airborne radio-echo sounding

Radio-echo sounding (RES) is an important tool in glaciology, it allows to determine ice thickness as well as the internal structure of ice sheets, ice shelves, and glaciers. Usually ground based RES is used for shallow ice bodies whereas airborne RES is used for pre-site surveys for deep ice core d...

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Bibliographic Details
Main Authors: Steinhage, Daniel, Nixdorf, Uwe, Miller, Heinrich
Format: Conference Object
Language:unknown
Published: 2003
Subjects:
DML
Online Access:https://epic.awi.de/id/eprint/9009/
https://hdl.handle.net/10013/epic.19524
Description
Summary:Radio-echo sounding (RES) is an important tool in glaciology, it allows to determine ice thickness as well as the internal structure of ice sheets, ice shelves, and glaciers. Usually ground based RES is used for shallow ice bodies whereas airborne RES is used for pre-site surveys for deep ice core drill sites or to map the ice thickness of large areas. Another advantage of RES is that the same material properties which cause reflections within the ice can be measured at an ice core using dielectrical profiling (DEP). Therefore RES measurements can be directly linked to ice cores. This also allows direct comparison of two ice cores connected by a continuous RES profile and to transfer paleoclimatic information derived from an ice core at a single location onto an extended area.In Dronning Maud Land (DML) at at 0º and 75º S, 2850 m a.s.l. at deep ice core is currently drilled at Kohnen Station as part of European Project for Ice Coring in Antarctica (EPICA). The drill site is located in an area with relatively high accumulation of . approximately 62 kg m-2 a-1 in the Atlantic sector of Antarctica at an ice divide originating at Dome Fujji, 39.7º E and 77.3º S, 3810 m a.s.l. This yields to a high temporal resolution of the ice core. The ice thickness of 2750 m is sufficient for ice core covering more than a fill glacial cycle (110 ka). At the starting point of the ice divide at Dome Fuji, 3810 m a.s.l.,, another deep ice core drill site is located. Due to the low accumulation at that location of 21 kg m-2 a-1, the obtained 2503 m long ice core covers a time span of approximately 330 ka.We will present RES profiles measured by the Alfred Wegener Institute (AWI) between 1999-2003 which allow a direct comparison of the age depth scales of both deep ice core drill sites by tracing isochrones along the intersecting profiles along the ice divide. As well as maps of different internal horizons and derived properties.