Crustal velocity field in Baza and Galera faults: A new estimation from GPS position time series in 2009 - 2018 time span

Abstract

The Baza and Galera faults are two active geologic structures located in the central area of the Betic Cordillera (Southern Spain). The goal of our research is to constrain the activity of this faults from high quality GPS measurements to obtain precise deformation rates. In 2008 a GPS survey – mode network was installed to monitor this area. In previous works, we presented a velocity field based on the analysis of some GPS campaigns. Here we show the new results computed from nine GPS campaigns in the timespan 2009-2018. The measurements were done in September 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2017 and 2018. The data process and analysis were performed in Precise Point Positioning by using GIPSYX 1.6 software. GIPSY is a GNSS-inferred positioning software developed by the Jet Propulsion Laboratory. Then, the new estimation of the crustal velocity field is computed from the IGb14 time series by SARI software. The model applied to the original time series, using weighted least squares, consists of an intercept, a site rate and an offset to account for an antenna change. The error term is composed of white noise and temporally correlated random error. The colored noise is described by a random-walk process. We have assumed a typical magnitude for this process of 1.0 mm/√yr. Finally, we discuss the implications of the new results for the tectonic setting and seismic hazard assessment of this key tectonic area of the Betic Cordillera.