Structure of Continental Lithosphere

Team Leader: Dr. Petr Kolínský

 

The team deals with detailed modelling of the continental lithosphere by applying multi-method and inter-disciplinary approach. We have coined a holistic approach to the lithosphere research by combining our seismological results with relevant findings in other geophysical disciplines, as well as in tectonics, petrology and geochemistry. We search how the crust and the underlying mantle lithosphere were formed and evolved during plate-tectonic processes since the origin of primordial continents.
We participated in the pan-European multidisciplinary project AlpArray, which focused on the Alps and adjacent areas. The project was based on a large-scale passive seismic experiment and tested the linkage of the Earth’s surface and the mantle by integrating 3D imaging of the entire crust-upper mantle system with geologic observations and modeling.
The AdriaArray experiment, during which the entire Adria plate is covered by a dense network of seismic stations, belongs among the most recent activities of the team. The array collects data to answer questions about the structures of the plate itself, as well as its interaction with surrounding plates.The program is based on a large-scale passive seismic experiment and tests linkage of the Earth surface and the mantle by integrating 3D imaging of the entire crust-upper mantle system with geologic observations and modelling.

Since 1991 we have organized and participated in several international passive seismic experiments, covering vast regions of Europe, from Scandinavia through the Bohemian Massif to the Mediterranean. The team has participated in building the IG CAS pool of mobile seismic stations MOBNET, installed in targeted passive experiments in regions of different tectonics. The temporary dense networks record seismic waves, which illuminate the Earth and allow us to model the structure of the crust and upper mantle. Tomography images of the upper mantle are based on deviations of body-wave propagation and incorporate effects of seismic anisotropy. Fabrics of the continental mantle lithosphere are studied by joint inversion and/or interpretation of body-wave anisotropic parameters (directional variations of body-wave propagation and shear-wave splitting) and novel coupled anisotropic-isotropic tomography. The almost ubiquitous large-scale seismic anisotropy of the lithosphere and the underlying mantle stems from a systematic orientation of minerals and rocks, particularly olivine in the mantle. Ambient noise tomography and receiver functions are applied to retrieve 3D models of the crust. Resulting anisotropic models of the lithosphere and the upper mantle can be used in interpretations of other geoscience disciplines.