Magnetotelluric measurements from the Grunehogna Craton of East Antarctica

• Main Authors: Ritter, O., Fromm, Tanja, Weckmann, U., Kütter, S.
• Format: Conference Object
• Language: unknown
• Published: 2019
• Subjects: Antarc*; Antarctica; Dronning Maud Land; East Antarctica; Ice Sheet; Ice Shelf; Ice Shelves; Sea ice; Weddell Sea
• Online Access: https://epic.awi.de/id/eprint/50762/; https://hdl.handle.net/10013/epic.d99a3d5c-3c0e-4816-86e7-1a18206d7f9c

The Grunehogna Craton (GC) in the Atlantic sector of East Antarctica is situated in western Dronning Maud Land between approximately 2 and 15°W. The GC was part of or adjacent to the Archaean Kalahari Craton of southern Africa and became attached to Antarctica during the Jurassic breakup of Gondwana. We report on magnetotelluric (MT) measurements from 20 sites in the vicinity of Neumayer III research station, which is located on the Ekström Ice Shelf (EIS) at the eastern coast of the Weddell Sea. The MT data was collected using broad band instruments with an average site spacing of 5 km. Contrary to sea ice, ice shelves originate from a glacier or ice sheet that flows down to a coastline and onto the ocean surface. Therefore ice shelves are firmly attached to the land masses and the EIS overlays in parts the GC. The MT data, particularly the inductions vectors, clearly mark the transition from areas which are underlain by sea water and where the ice is directly grounded on the craton. The MT sites located on the GC show generally high resistivity, which can be expected for Archean rocks.