Spacial and energetic trends of the microearthquakes activity in the Central Betics

Active tectonics in the Sierra Nevada (Betic Cordillera, SE Spain): Insights from geomorphic indexes and drainage pattern analysis

“…The Granada basin, located to the west of the Sierra Nevada ( Figs. 1 and 2), presents the highest seismic activity in all of the Iberian Peninsula, with a great number of earthquakes of low to moderate magnitude (M b ≤ 5.5;de Miguel et al, 1989). Focal mechanisms indicate a present-day stressstate dominated by radial extension or by an NE-SW oriented extensional axis Muñoz et al, 2002).…”

Late Quaternary large-scale rotational slides induced by river incision: The Arroyo de Gor area (Guadix basin, SE Spain)

“…After establishing the possible determining factors motivating the existence of the Arroyo de Gor rotational slides, a plausible triggering mechanism needs to be invoked. Earthquakes can be reasonably discarded on the grounds that (i) no faults with Pleistocene-Holocene activity can be observed in this area, (ii) historical and instrumental seismicity in the Betic cordillera is of low to moderate intensity with maximal expected magnitudes around 6 (De Miguel et , 1989;Sanz de Galdeano et al, 2003), and (iii) present-day seismicity is concentrated south and east of the Guadix basin Muñoz et al, 2002;Serrano et al, 2002). In our opinion, the most probable triggering factor for the landslides studied consists in periods of heavy rains.…”

1-18 HzLgattenuation in the Granada Basin (southern Spain)

“…The dominating fault systems follow the E-W direction (Figs 1 and 6). The statistical azimuth of the alignments observed from Landsat images (De Miguel et al 1989) and the mapping of fractures, present a maximum for the set of directions N90-llOW (Fig. 6).…”

“…These faults are produced by the collision between the Euroasiatic and the African plates, producing the greatest magnitude earthquakes in the area. On the eastern border there is a moderate seismic system of fractures with a N10-30E direction, and scattered around the zone there are two systems with directions N40-60W and N30-40E, produced by the compressive movement of the Iberian Penninsula (De Miguel et al 1989).…”