Relationships between upper mantle thermal structure and crustal deformation in Western and Central Europe – new interpretations of seismic tomography models

Abstract

Mantle shear-wave velocity models derived from seismic full waveform inversion methods reveal a very heterogeneous lithosphere-asthenosphere system beneath intracontinental Western and Central Europe north of the Alps. To better understand the physical state of the upper mantle in this region, we convert shear-wave velocity models to thermodynamically consistent temperature and density configurations using a Gibbs's free energy minimization approach. The inferred physical state of the lithosphere-asthenosphere system is then investigated for its consequences on past and present-day crustal deformation. For instance, a thermal lithosphere-asthenosphere boundary that varies in depth between > 200 km in the southern North Sea and < 80 km close to the Alpine deformation front raises important questions regarding the causes for this thermal disequilibrium and its effects on the thermomechanical stability of the crust. In particular, we will discuss the imaged mantle thermal anomalies in light of the inherited crustal structure and its effects on ongoing deformation (including seismicity) in this intracontinental setting.

Authors 6

1. Judith Bott corresponding

   GFZ Helmholtz Centre for Geosciences

   Affiliation as printed

   GFZ German Research Centre for Geosciences, Basin Modelling, Potsdam, Germany (judith.sippel@gfz-potsdam.de)

2. Magdalena Scheck‐Wenderoth corresponding Aachen Faculty of Georesources and Material Engineering

   RWTH Aachen University · GFZ Helmholtz Centre for Geosciences

   Affiliation as printed

   Faculty of Georesources and Material Engineering, RWTH Aachen, Aachen, Germany

   GFZ German Research Centre for Geosciences, Basin Modelling, Potsdam, Germany (judith.sippel@gfz-potsdam.de)

3. Ajay Kumar corresponding

   GFZ Helmholtz Centre for Geosciences

   Affiliation as printed

   GFZ German Research Centre for Geosciences, Basin Modelling, Potsdam, Germany (judith.sippel@gfz-potsdam.de)

4. Mauro Cacace corresponding

   GFZ Helmholtz Centre for Geosciences

   Affiliation as printed

   GFZ German Research Centre for Geosciences, Basin Modelling, Potsdam, Germany (judith.sippel@gfz-potsdam.de)

5. Sebastian Noe corresponding

   ETH Zurich

   Affiliation as printed

   Seismology and Wave Physics Group, ETH Zürich, Zürich, Switzerland

6. Jan Inge Faleide

   University of Oslo

   Affiliation as printed

   Department of Geosciences, University of Oslo, Oslo, Norway