Peligrosidad sísmica de la Falla de Granada
- Jose Miguel Azañon Hernandez 1
- Julian García Mayordomo 2
- Juan Miguel Insua Arévalo 3
- Martín Jesús Rodríguez Peces 3
-
1
Universidad de Granada
info
-
2
Instituto Geológico y Minero de España
info
-
3
Universidad Complutense de Madrid
info
ISSN: 0214-1744
Year of publication: 2013
Issue Title: Geología y arqueología de terremotos
Volume: 27
Issue: 3-4
Pages: 13-20
Type: Article
More publications in: Cuaternario y geomorfología: Revista de la Sociedad Española de Geomorfología y Asociación Española para el Estudio del Cuaternario
Abstract
The City of Granada is placed at the margin of a flat area known as the Granada Basin (Betic Cordillera, SE Spain) surrounded by mountains. The seismic activity in the Granada Basin is high, with a large number of earthquakes, all of them of moderate to low magnitude (mb ≤ 5.5). Historically, earthquakes in this area have produced important material damage and human casualties; however, it is hard to evaluate their magnitude. Seismicity has its origin mostly at depths between 5 and 17 km and the focal mechanisms indicate a present stress field dominated by a tensional tensor with an associated NE-SW extensional axis. The sedimentary cover of the Granada Basin is mostly coeval with the activity of faults that bound the basin, which have controlled the stratigraphic architecture. These faults are normal, mostly with a NW-SE orientation, and dipping towards the SW. Basinwards migration of the extensional front has exhumed the footwalls of older faults, uplifting the previous Tortonian sedimentary cover, which presently outcrops as emerged ranges at the margins of the basin. This work presents preliminary results of a aleoseismic study of the Granada Fault, an NW-SE active normal fault that produces a Plio-Quaternary throw of 300 m. According to these data, slip rate has been estimated in 0.38 mm/yr. Several paleosoils, Pleistocene in age, have been affected by this fault. These paleosoils were sampled and dated using the hermoluminiscence method to constrain these estimates. Three different seismic events can be recognized from the accumulative throw. The vertical slip per event ranges from 5 to 7 cm. Following empirical relationships, a moment magnitude between 5.9 and 6.0 can be preliminary assessed for these events.
Bibliographic References
- Argus, D.F.; Gordon, R.G.; DeMets, C.; Stein, S. (1989). Closure of the Africa-Eurasia-North America plate motion circuit and tectonics of the Gloria Fault. Journal of Geophysical Research, 94, 5585-5602.
- De la Higuera, A.; Morales Delgado, A. (1999). La Almunia de los Alijares según dos autores árabes: Ibn Asim e Ibn Zamrak. Cuadernos de la Alhambra, 35, 31-48.
- DeMets, C.; Gordon, R.G.; Argus, D.F.; Stein, S. (1994). Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions. Geophysical Research Letters, 21, 2191-2194.
- De Miguel, F.; Vidal, F.; Alguacil, G.; Guirao, J.M. (1989). Spatial and energic trends of the microearthquakes activity in the Central Betics. Geodinamica Acta, 3, 87-94.
- Galindo-Zaldívar, J.; Jabaloy, A.; Serrano, I.; Morales, J.; González Lodeiro, F.; Torcal, F. (1999). Recent and present-day stresses in the Granada Basin (Betic Cordilleras): example of a late Miocene - present-day extensional basin in a convergent plate boundary. Tectonics, 18, 686-702.
- Galindo-Zaldívar, J.; Gil, A.J.; Borque, M.J.; González Lodeiro, F.; Jabaloy, A.; Marín Lechado, C.; Ruano, P.; Sanz de Galdeano, C. (2003). Active faulting in the internal zones of the central Betic Cordilleras (SE, Spain). Journal of Geodynamics, 36, 239-250.
- Günter, N.; Skowronek, A. (2001). Sediment-soil sequences in the Granada Basin as evidence for long- and short-term climatic changes during the Pliocene and Quaternary in the Western Mediterranean. Quaternary International, 78, 17-32.
- Herraiz, M.; De Vicente, G.; Lindo-Naupari, R.; Giner, J.; Simón, J.L.; González-Casado, J.M.; Vadillo, O.; Rodríguez-Pascua, M.A.; Cicuéndez, J.I.; Casas, A.; Cabañas, L.; Rincón, P.; Cortés, A.L.; Ramírez, M.; Lucini, M. (2000). The recent (upper Miocene to Quaternary) and present tectonic stress distributions in the Iberian Peninsula. Tectonics, 19, 762-786.
- Martín, J.M.; Braga, J.C. (1997). Sierra Nevada: Historia del levantamiento de un relieve deducida de las unidades conglomeráticas de su borde. En: Avances en el conocimiento del Terciario Ibérico (Calvo, J.P.; Morales, J.; eds.), 117-120.
- Martínez-Martínez, J.M.; Soto, J.I.; Balanyá, J.C. (2002). Orthogonal folding of extensional detachments: structure and origin of the Sierra Nevada elongated dome (Betics, SE Spain). Tectonics, 21, 3-1–3-20.
- Morales, J.; Serrano, I.; Vidal, F.; Torcal, F. (1997). The depth of the earthquake activity in the Central Betics (Southern Spain). Geophysical Research Letters, 24, 3289-3292.
- Morales, J.; Serrano, I.; Jabaloy, A.; Galindo-Zaldívar, J.; Zhao, D.; Torcal, F.; Vidal, F.; González Lodeiro, F. (1999). Active continental subduction beneath the Betic Cordillera and the Alborán Sea. Geology, 27, 735-738.
- Muñoz, D.; Cisternas, A.; Udías, A.; Mezcua, J.; Sanz de Galdeano, C.; Morales, J.; Sánchez-Venero, M.; Haessler, H.; Ibañez, J.; Buforn, E.; Pascual, G.; Rivera, L. (2002). Microseismicity and tectonics in the Granada Basin (Spain). Tectonophysics, 356, 233-252.
- Peláez Montilla, J.A.; Gil, A.J.; Sanz de Galdeano, C.; Rodríguez Caderot, G. (2002). Condicionantes en el diseño de una red geodésica para el control de una falla normal: aplicación a la falla de Granada. Proceedings of the 3ª Asamblea Hispano Portuguesa de Geodesia y Geofísica, Valencia (Spain), 51-55.
- Rodríguez Fernández, J.; Sanz de Galdeano, C. (2001). La Cuenca de Granada. Interpretación de su estructura a partir de perfiles sísmicos. En: La cuenca de Granada: Estructura, Tectónica activa, Sismicidad, Geomorfología y dataciones existentes (Sanz de Galdeano, C.; Peláez Montilla, J.A.; López Garrido, A.C.; eds.), 109-116.
- Rodríguez Fernández, J.; Sanz de Galdeano, C.; Fernández, J. (1989). Genesis and evolution of the Granada Basin (Betic Cordillera, Spain). En: Intermontane basins: Geology and resources (Thauasuthipitak, T.P.; Ounchanum, P.; eds.), 294-305.
- Sanz de Galdeano, C.; Peláez Montilla, J.A.; López Casado, C. (2003). Seismic potential of the Main Active Faults in the Granada Basin (Southern Spain). Pure and Applied Geophysics, 160, 1537-1556.
- Serrano, I.; Zhao, D.; Morales, J. (2002). 3-D crustal structure of the extensional Granada Basin in the convergent boundary between the Eurasian and African plates. Tectonophysics, 344, 61-79.
- Wells, D.L.; Coppersmith, K.J. (1994). New empirical relationships among magnitude, rupture length, rupture area, and surface displacement. Bulletin of the Seismological Society of America, 84, 974-1002.