Final Activity Report Summary - SEADOME (Seismic Anisotropy, Plate-Driving Forces and the Motion of Europe)
This project studied seismic anisotropy under Eastern Europe with the goal to better understand structure and deformation under the Eastern European craton. This was important because the craton, as a thick lithospheric block, controls mechanical interaction between the European plate and the deeper mantle. At the surface, the craton represents the geologically stable portion of the European, i.e. Western Eurasian, continent and it consists of the major part of Scandinavia and a large part of Eastern Europe. It is subdivided into the Eastern European platform that is overlain by sediments and its shield regions, namely the Fennoscandian and Ukranian shields, which are not. While the craton was hardly deformed for half a billion years, the structure of its mantle portion apparently changed substantially throughout geological history, probably because of the mechanical interaction with the deeper mantle. There are major rift zones and thick sedimentary basins are formed in response to the changes in structure of lithosphere and upper mantle.
The main observational tool that was used in the project was shear-wave splitting, a technique that allowed for the determination of seismic anisotropy in the subsurface based on recorded three-component seismograms. Based on its seismic anisotropy, we found that the Eastern European craton was apparently subdivided into two parts with distinct lithosphere:
1. a northern part, including Fennoscandia and the northern portion of the Eastern European platform (EEP), and
2. a southern part, that included the southern portion of the EEP and the Ukrainian shield. The nature of these two lithospheric blocks would be studied during the third project year.
In this project we developed computer tools to perform shear-wave splitting measurements efficiently. In particular, the code SplitLab performed the entire processing from requesting seismological waveform data, data processing and results post-processing. The code was distributed without restriction to the scientific community.
The main observational tool that was used in the project was shear-wave splitting, a technique that allowed for the determination of seismic anisotropy in the subsurface based on recorded three-component seismograms. Based on its seismic anisotropy, we found that the Eastern European craton was apparently subdivided into two parts with distinct lithosphere:
1. a northern part, including Fennoscandia and the northern portion of the Eastern European platform (EEP), and
2. a southern part, that included the southern portion of the EEP and the Ukrainian shield. The nature of these two lithospheric blocks would be studied during the third project year.
In this project we developed computer tools to perform shear-wave splitting measurements efficiently. In particular, the code SplitLab performed the entire processing from requesting seismological waveform data, data processing and results post-processing. The code was distributed without restriction to the scientific community.