Assessment of the deep structure of the lithosphere beneath the Iberian Peninsula: The IBERARRAY seismic platform

Category Other
Group GSI.IR
Location International Geological Congress,oslo 2008
Author Carbonell, Ramon۱; Pazos, Antonio۲; Morales, José۳; Garcia-Lobon, Jose Luis۴; Cordoba, Diego۵; Pulgar, Javier۶; Diaz, Jordi۷; Villaseٌor, Antonio۷; Gallart, Josep۷
Holding Date 27 September 2008

Assessment is the process of documenting, usually in measurable terms. The seismic part of the IBERARRAY instrumentation platform aims to acquire new seismic data with an unprecedented resolution to assess and unravel the lithospheric structure of the Iberian Peninsula and its margins. The dataset collected should provide new constraints on the processes, nature and dynamics of the Earth’s interior. They are an asset to understand the evolution of a wide range of surface processes, including the very existence of plate tectonics, intraplate volcanism, magnetic events from the short to the longterm, the state of stress in the lithosphere, and vertical motion from basin to continental scales manifested in uplift and subsidence with impact on drainage systems and geomorphology.
The seismic Iberarray platform is composed by a dense network of broad band recorders. The plan is to deploy the stations in an approximately 60x60 km grid to cover the entire study area in three stages. The first stage, which has already been completed, involved deployment of 55 BB stations (35 in the Peninsula and 20 in northern Morocco). This network is dedicated to acquire data in the area of complex interaction between the European and African continental plates. The digital seismic network consists of Taurus recording units and Trilium 120s sensors (both from Nanometrics). Earthquake data at local, regional and teleseismic scales will be analyzed using different methodologies aiming at different objectives. A first phase would be an increase in the precision on the location of the regional seismicity by considering waveform analysis and other advanced techniques.
A special emphasis will be attributed to the use of tomographic inversion schemes to obtain 3 dimensional maps of physical properties (P and S seismic wave velocities) to study large scale structural elements within the Iberian Peninsula. This includes research using travel times and waveforms of P and S arrivals at different scales (local, regional and global) and surface waves, using dispersion measurements and studies dealing with the background/environmental noise. In addition, receiver function analysis for seismic imaging of deep lithospheric features and splitting analysis of shear-wave arrivals will also be applied.