Tectonic studies made in intraplate Europe have shown that this area is more active
than would be expected from its location far away from plate boundaries.The first
strength map showed that the European lithosphere is characterized by major spatial
mechanical strength variations, with a pronounced contrast between the strong
lithosphere of the East-European Platform (EEP) east of the Tesseyre-Tornquist Zone
(TTZ) and the relatively weak lithosphere of Western Europe.
In order to improve the results previously obtained, we have constructed a new
crustal model, in which we implement the results of recent seismic studies. The new
crustal model consists for continental realms, of two or three crustal layers and
an overlying sedimentary cover layer, whereas for oceanic areas one crustal layer
is used. The results of deep seismic reflection and refraction and/or receiver
function studies are used to define the depth of the crustal interfaces and P-wave
velocity distribution. The Moho map is reconstructed by merging the most recent
maps compiled for the European regions. To each layer of the model we associate a
density value and corresponding lithology. Strong differences are found in the
structure of the Baltica crust of the EEP and the Variscan crust of Western Europe.
The first one has an high thickness (42-44 km) and an high velocity of the lowest
layer (Vp~7.1km/s). By contrast, the second one is thinner (30-35 km) and is
generally characterized by slower P-wave velocity in the lower crust (Vp~6.8km/s).
Seismic tomography data are used to get the location of the lithosphere-
astenosphere boundary and calculate the temperature distribution. These results,
jointly with the new crustal model, allowed us to refine the previous strength map.
Furthermore, the gravity effect of the crustal model is calculated and removed from
the observed gravity field in order to get residual mantle anomalies. These
anomalies distribution are compared with the new strength results. Negative mantle
gravity anomalies and relative low strength values characterize Western Europe,
while the reverse is true for Eastern Europe. Large differences exist also for
specific tectonic units: a pronounced contrast in lithosphere properties is found
between the strong Adriatic plate and the weak Pannonian Basin area, as well as
between the Baltic Shield and the North Sea rift system.