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Mikhail Kaban, GFZ (Germany)
Magdala Tesauro, GFZ (Germany)
Ivan Koulakov, IPGG SB RAS (Russian Federation)
Sierd Cloetingh, Vrije Universiteit (Netherlands)
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A new integrative 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). It offers a starting point in any kind of numerical modeling, which has to resolve a trade-off between crustal and mantle effects. 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 and residual topography 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 addition we use a new tomographic model for P and S velocity anomalies beneath Europe, which is also a-priori corrected for the crustal structure using the EuCRUST-07 model (Koulakov et al., 2008). Temperature variations in the upper mantle are then determined based on the seismic tomography data. We estimate the effects of mantle temperature anomalies on the gravity field and topography and remove it from the total fields. It 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. One important example is a strong positive density anomaly under significant part of the Alpine fold belt, which is likely related to remnants of the lithosphere plate.
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