Processing of shipborne magnetometer data and revision of the timing and geometry of the Mesozoic break-up of Gondwana = Auswertung schiffsfester Magnetometerdaten und die Neubestimmung des Zeitpunktes und der Geometrie des Mesozoischen Aufbruchs von Gondwana

• Main Author: König, Matthias
• Format: Other/Unknown Material
• Language: unknown
• Published: Alfred Wegener Institute for Polar and Marine Research 2006
• Subjects: Berichte zur Polar- und Meeresforschung; Reports on Polar and Marine Research; Weddell Sea
• Online Access: https://epic.awi.de/id/eprint/26172/; https://epic.awi.de/id/eprint/26172/1/Kni2006c.pdf; https://hdl.handle.net/10013/epic.24879; https://hdl.handle.net/10013/epic.24879.d001

Seafloor spreading anomalies in the world's ocean basins yieldcrucial information about the paleogeographic configuration of thecontinents and the development of ocean basins. Standard methodsfor measuring these variations are to apply ship towedmagnetometer systems or aircrafts. For the polar regions,magnetometer systems fixed to a vessel are more appropriate. Aprocessing sequence for the evaluation of magnetometer dataacquired onboard RV \emph{Polarstern} with a sensor system fixedto the ship is described in the first part of this thesis. In thesecond part, seafloor spreading anomaly data, measured by ship,aircraft and helicopter, in the South Atlantic region, are used toconstrain a geodynamic model for the Mesozoic break-up of Gondwanaand the development of the Weddell Sea Basin.Magnetometer data acquired onboard the German ice breaker andresearch vessel Polarstern have to be corrected for theship's interfering field caused by the hull and other steel partsof the ship. This correction is done by the calculation ofappropriate compensation coefficients. With the processing schemepresented in this thesis the ship's magnetometer data arecompensated and filtered to an accuracy of about 20nT at ahorizontal resolution of about 154m in quiet sea conditions.This makes the data suitable for a consistent interpretation ofsingle track data or further processing of a network of profiles.The compilation of a magnetic anomaly map and comparison withother high resolution magnetic anomaly data demonstrate thesuitability of the processed data to be used for detailedinterpretations of magnetic anomalies in geodynamic problems likethose encountered in the South Atlantic region and dealt with inthe second part of this thesis.A refined model for the break-up of Gondwana and the opening ofthe Weddell Sea is presented in the second part of this thesis.From an interpretation of a newly acquired extensive magneticanomaly data set in the eastern Weddell Sea, well constrained agesand orientations of seafloor spreading anomalies are used ...