GPS horizontal deformation model in the southern region of the Iberian Peninsula and northern Africa (SPINA)

Abstract

Global Navigation Satellite System (GNSS), and in particular Global Positioning System (GPS) technology, provides a powerful tool for studying geodynamic processes. As a consequence of GPS studies, it is now possible to analyze the interaction between tectonic plates in order to evaluate and establish the characteristics of their boundaries. In this study, our main interest is to focus on the time series analysis obtained from observations of GNSS-GPS satellites. Each GPS observation session provides topocentric geodetic coordinates (east, north, elevation) of the permanent stations that constitute the geodetic network established for this purpose. This paper shows a detailed topocentric coordinate time-series study for sites belonging to what we call the SPINA network, which stands for south of the Iberian Peninsula, north of Africa region. The series under study are processed by techniques of relative positioning with respect to the IGS (International GNSS Service) reference station located in Villafranca. These times series have been analyzed using filter processes, harmonic adjustments, and wavelets. A surface velocity field is derived from the time series of daily solutions for each station, whose observations span 8 years or longer. This allows us to obtain a horizontal displacement model to show the regional geodynamic main characteristics.