Analysis of helicopter and ship-borne magnetic data in the Amundsen Sea Embayment, West Antarctica

• Main Authors: Denk, Astrid, Gohl, Karsten, Wobbe, Florian
• Format: Conference Object
• Language: unknown
• Published: 2010
• Subjects: Amundsen Sea; Antarc*; Antarctic; Antarctica; Ice Sheet; Pine Island; Pine Island Bay; Thwaites Glacier; West Antarctica
• Online Access: https://epic.awi.de/id/eprint/23099/; https://hdl.handle.net/10013/epic.35892

In the last years, the Amundsen Sea sector of West Antarctica has attracted increasing attention due to the role of the marine-based West Antarctic Ice Sheet which partly drains into the Amundsen Sea. For instance, the Pine Island and Thwaites glacier systems exhibit an amplifying ice-flow velocity and a retreat of their grounding zones. Arising questions concern the regime of the underlying tectonically and magmatically formed basement which forms the controlling morphology geometry for past ice-sheet dynamics. Accurate models of the geodynamic-tectonic evolution contain some of the most important parameters for understanding and reconstruction of the paleoenvironment. The objectives comprise the identification of the boundaries between suspected crustal blocks and volcanic zones in Pine Island Bay. The glacier troughs and Pine Island Bay are thought to have developed along such tectonic boundaries.During two expeditions with RV Polarstern in the years 2006 and 2010 to West Antarctic continental margin, a considerable amount of magnetic data has been acquired in the Amundsen Sea, particularly in Pine Island Bay. In both years, the data acquisition was conducted with a permanent ship borne magnetometer system and a variable helicopter borne magnetometer system. Helicopter borne magnetic measurements were performed with a caesium vapour magnetometer, towed 30 m below the helicopter to avoid magnetic disturbances. During the flight campaign of 2010, in which 15000 km of flight data was gathered, a densification and supplement of the grid of 2006 containing 20000 km flight data, was achieved. The resulting grid covers an area of about 20000 km² and ranges from Pine Island Bay on the inner shelf to the outer shelf and above continental slope. Shipborne magnetic measurements were made by two fluxgate vector magnetometers, which are permanently mounted at the crow's nest of RV Polarstern. The data were sampled at one-second intervals. To take account of the influence of the metallic bulk of the ship, the ship ...