REGIONAL CONVERGENCE AND R&D INVESTMENT: APPLIED INVESTIGATION IN PORTUGAL

R&D investments are seen has having an enormous potential impact on the competitive position of regions and perhaps on regional convergence (or divergence) too. The aim of the paper is to study both the localization of R&D investments and regional income distribution among the NUTs 3 regions of Portugal to conclude if these variables are related or not. To study the spatial convergence (approximation) of per capita income (GDPpc) and R&D investments in the regions of Portugal, we use a standard methodology of spatial econometrics. We conclude that regions with higher GDPpc are not the same with the highest concentration of R&D investments, with the exception of the northern coastline. The R&D investments are geographically linked to the network of higher education institutions, especially in the interior regions of the country. The northern regions reveal more dynamic in terms of R&D, which apparently is not felt in the population's standard of living measured by GDPpc.

Inversion of ambient seismic noise HVSR to evaluate velocity and structural models of the Lower Tagus Basin, Portugal

During its history, several significant earthquakes have shaken the Lower Tagus Valley (Portugal). These earthquakes were destructive; some strong earthquakes were produced by large ruptures in offshore structures located southwest of the Portuguese coastline, and other moderate earthquakes were produced by local faults. In recent years, several studies have successfully obtained strong-ground motion syntheses for the Lower Tagus Valley using the finite difference method. To confirm the velocity model of this sedimentary basin obtained from geophysical and geological data, we analysed the ambient seismic noise measurements by applying the horizontal to vertical spectral ratio (HVSR) method. This study reveals the dependence of the frequency and amplitude of the low-frequency (HVSR) peaks (0.2–2 Hz) on the sediment thickness. We have obtained the depth of the Cenozoic basement along a profile transversal to the basin by the inversion of these ratios, imposing constraints from seismic reflection, boreholes, seismic sounding and gravimetric and magnetic potentials. This technique enables us to improve the existing three-dimensional model of the Lower Tagus Valley structure. The improved model will be decisive for the improvement of strong motion predictions in the earthquake hazard analysis of this highly populated basin. The methodology discussed can be applied to any other sedimentary basin.