Results obtained from the multiple geodetic observations at Lorca (Murcia, Spain) subsidence area

Trabajo presentado en el AGU (American Geophysical Union) Fall Meeting: Advancing Earth and Space Science, celebrado en Washington D.C. (Estados Unidos), del 10 al 14 de diciembre de 2018The Lorca region, located in the Alto Guadalentín Basin, southern Spain, shows the highest subsidence rates recorded in Europe (about 10 cm/yr). It is produced by a long-term aquifer exploitation (González and Fernández, 2011; Bonì et al., 2014). This process has been studied in various works using interferometric synthetic aperture radar (InSAR) with images acquired from different satellites (ERS and ENVISAT radar data spanning the 1992 – 2007 period; ALOS PALSAR data for the period 2007–2010; and COSMO-SkyMed data for the period 2011–2012). González et al. (2012) established a relationship between the crustal unloading produced by the groundwater overexploitation and the stress change on the regional active tectonic faults in relation with the May 2008 Lorca earthquake. Those previous studies, based on InSAR and using either ascending or descending acquisitions, assumed that the surface displacement direction is entirely vertical. However, it is important to obtain the complete 3D motion field in order to perform a correct interpretation of the observations, as well as to carry out an advanced numerical model of the aquifer evolution, to be considered for sustainable management plans of groundwater resources and hazard assessments. To achieve this goal, GNSS surveys have been carried out from 2015 to 2018, showing the regional 3D displacement field associated to the exploitation of the aquifer (Prieto et al., 2016; Fernández et al. 2017). Also, simultaneous ascending and descending InSAR observations have been used, along with structural gravimetry (Camacho et al., 2015) and microgravity to study the subsidence area in a more complete geodetic way. We present the results obtained from all those techniques, their comparison, and the interpretation results using different inversion techniques (Tiampo et al., 2011; Camacho et al., 2011, 2015; Cannavò et al., 2015).Peer reviewe