Crustal and Thermal Heterogeneities Across the Fram Strait and the Svalbard Margin

Abstract

The lithospheric structure of the Fram Strait and the extent from the Knipovich Ridge to the Barents Sea shelf and Svalbard are poorly understood. Several multi-geophysical investigations from various campaigns since the 90s along the Western Barents Sea margin and the Northeast Greenland margin resulted in insufficient and contradicting interpretations of the crustal and upper mantle settings in the oceanic and continental domains. New airborne magnetic data across the Knipovich Ridge and west of Svalbard provide new insights, reveal the complexity of the seafloor spreading history of the Arctic Atlantic Ocean, and indicate a European-Eurasian continent-ocean boundary located ∼150 km farther west than previously suggested. This new location of the continent-ocean boundary prompted to revise the existing 2-D seismic interpretations in terms of crustal domains and tectono-stratigraphic setting. This is tested using joint 2-D gravity and magnetic field modeling to derive an improved crust-mantle model of the study. One recently acquired combined 2-D controlled source electromagnetic/magneto-telluric (CSEM/MT) profile across the Mohns Ridge was also modeled with potential field data and provided new insights into the tectonic settings of the crust and the mantle thermal anomalies. This study proposes to unify the various seismic and CSEM/MT interpretations using the new aeromagnetic compilation.