Gravity modelling of the crust and upper mantle for understanding of tectonic processes: a case study for Europe

摘要

A new gravity model of the European lithosphere has been constructed based on the analysis of several data sets, which are principally improved compared to previous studies. The new reference crustal model for Western and Central Europe (EuCRUST-07) has been constructed based on integration of nearly all existing seismic determinations in the area (Tesauro et al. 2008). The new gravity field model is based on combination of the satellite (CHAMP, GRACE) and existing terrestrial data. We use the data on the lithosphere structure to estimate gravity effect of mantle density anomalies and to characterize principal factors controlling mantle heterogeneity. The improved residual mantle gravity anomalies are estimated after removing of the crustal effect from the observed field. These anomalies reflect the effect of mantle density variations, which are induced by temperature and compositional anomalies. In the next stage we estimate a gravity effect of temperature variations in the upper mantle which are determined based on the seismic tomography data. This provides a possibility to discover compositional density anomalies in the upper mantle. Some features of the composition density distribution, which are invisible in the seismic tomography data, are for the first time detected. In future we are going to use this method to investigate structure of the crust and upper mantle in Central and Southeastern Asia.