Multi-temporal InS AR for deformation monitoring of the Granada and Padul faults and the surrounding area (Betic Cordillera, southern Spain)

摘要

The quantification of low rate active tectonic structures is a major target of geodetic and geological studies to improve the knowledge of seismic hazards. The central Betic Cordillera (southern Spain) is affected by moderately active tectonic structures and seismicity. Part of this seismic activity is produced by several NW-SE normal faults located in the E of the Granada Basin. Here, we apply Multi-temporal InSAR (MTI) data to quantify the deformation produced by the Granada fault and the Padul fault zones and the surrounding area. The Granada NW-SE active normal fault zone, 17 km in length, crosses the city of Granada, a very sensitive area from a seismic hazard point of view due to the population of the Granada town. At the Padul fault, there is no geodetic evidence of contemporary motion. Considering the evidence of recent activity from geologic data, this fault may experience discontinuous motion with a different seismogenic character. Despite the InSAR uncertainties, InSAR results are consistent with the estimated geologic deformation rates lower than 1 mm/yr. Our results also confirm previous InSAR studies in the Otura area showing an estimated average annual velocity along the SAR line-of-sight of up to 10 mm/year anthropogenic subsidence.