Constraints on the geodynamic evolution of the northern North Atlantic

• Main Authors: Ehlers, Birte-Marie, Jokat, Wilfried, Leinweber, Volker Thor
• Format: Conference Object
• Language: unknown
• Published: 2007
• Subjects: Arctic; Arctic Ocean; Fram Strait; Greenland; North Atlantic; Svalbard
• Online Access: https://epic.awi.de/id/eprint/17124/; https://hdl.handle.net/10013/epic.26973

The ocean region of the Fram Strait between Svalbard and Greenland is the only deep water connection between the Arctic Ocean and the North Atlantic. A detailed understanding of this region, however, is difficult due to the absence of clear marine magnetic and other geophysical data. Within the last years the Alfred Wegener Institute conducted several geophysical surveys to achieve a more systematic geophysical data set in order to solve some of the remaining problem in the Fram Strait and the subsequent basins (Molloy and Boreas basins). Typical for the magnetic signature of the Boreas Basin is the complete absence of continuous sea floor spreading anomalies. Furthermore, the spreading in this basin seemed to be asymmetric and/or a ridge jump occurred. Similar problems exist in the Molloy Basin and the Fram Strait.In this contribution we present new aeromagnetic data grid, seismic reflection data and existing gravimetric data that provide new insights into the geodynamic evolution of this area. Seismic reflection lines crossing the entire Molloy and Boreas basins show a deep axial valley and very rough basement topography. Combining the depth information of the seismic reflection data with the age information of the aeromagnetic data, the thermal subsidence for oceanic crust corrected for the sediment load fits the observed basement depth reasonably well. A subsequent roughness analysis of the basement topography show that the values fall into the same class as the ultra-slow spreading Gakkel Ridge. Furthermore, the spreading rates, which are typical for the calculated roughness, are applied to constrain the spreading history of these basins. The latest results of this analysis for the Fram Strait and its subsequent basins are shown.