The NARS array : a seismic experiment in Western Europe

Abstract

Due to the rapid development of portable, digital seismographs it has recently become possible in global seismology to install and operate a large scale temporary array of seismic stations. This thesis describes the design and operation of the first experiment of this kind: the Network of Autonomous Recording Stations (NARS). The aim of NARS is to measure the dispersion of surface waves, especially higher modes, and to obtain through linearized inversion a shear-velocity and density model for the upper mantle under the West European platform. The existence of such a regional model opens the possibility to test different current hypotheses about the structure and composition of the upper mantle. Inversion of previous measurements of the dispersion of surface waves in Western Europe resulted in an average model for the West European platform including the Scandinavian shield. Combination of the measurements presented in this thesis with the older dataset opens the possibility to investigate differences between the shield and platform structure.