ALPARRAY – AN INTERNATIONAL PROGRAMME OF SEISMOLOGICAL AND GEOPHYSICAL INVESTIGATIONS IN THE GREATER ALPINE AREA

Abstract

The internal structure of the Earth is studied mainly by the analysis of seismic waves. These are recorded by perma­nent seismological stations, but they are very unevenly distributed. To improve geophysical models, observations of seismicity with additional seismographs for a couple of years is meaningful. The development of portable measuring equipment in the past two decades has given rise to numerous studies of deep lithospheric structures worldwide. For a better understanding of the complex lithosphere plate boundaries in Europe, the most interesting studies are of the Alps, which were formed by the collision of the Eurasian and the fragmented African tectonic plates. Within the AlpArray research programme, 600 additional seismographs were deployed in 11 countries, which measured earthquakes for two years. The recorded data enabled in-depth studies, especially using seismic tomography and surface wave dispersion methods. They resulted in detailed 3D models of seismic velocity and density distribution, supplemented by gravimetric and other geophysical studies. All this together contributes to more accurate locations of earthquake hypocentres, knowledge of seismotectonics, and better seismic hazard assessment.