Tomographic Inversion of Pn Waves beneath Southern Scandinavia

Scandinavian Mountain Range is located at the continental margin of Eurasian plate. This area is part of the Baltic shield so topography is expected to be generally low, but this is not the case here. Absence of active tectonics in this area and results from some previously conducted geophysical studies suggests that the cause of this topography is merely not a pure crustal phenomenon. There can be some mantle process that caused and sustained this topography. The objective of this study is to analyze the upper mantle composition and heterogeneities by using the concept of Pn tomography (by imaging P wave velocities in the upper mantle). Results of mantle velocity imaging indicates a general trend of low velocity in the thinner/younger part of Baltic shield whereas high velocity in the thicker/older parts. Velocity structure beneath southern and central Norway is anomalous (having low velocity) with respect to the rest of Baltic shield. These low velocities are probably connected to Iceland plume in the west by a narrow channel where low velocities are related to hot and shallow mantle beneath the plume