@article{ProBufornCescaetal.2014,
  author    = {Pro, C. and Buforn, Elisa and Cesca, Simone and Sanz de Galdeano, C. and Udias, A.},
  title     = {Rupture process of the Lorca (southeast Spain) 11 May 2011 (M (w)=5.1) earthquake},
  series = {Journal of seismology},
  volume    = {18},
  journal   = {Journal of seismology},
  number    = {3},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1383-4649},
  doi       = {10.1007/s10950-014-9421-8},
  pages     = {481 -- 495},
  year      = {2014},
  abstract  = {On 11 May 2011, a M (w) = 5.1 earthquake shook the town of Lorca (SE Spain) causing a disproportionately large damage for its magnitude. In order to contribute to knowledge of the behavior of the active faults present in the region and define the parameters which control their motion, we made a detailed study of the rupture process of this earthquake from inversion of body waves at regional and teleseismic distances. Ground motion displacements obtained in this way are in agreement with near-field strong motion data and GPS observations recorded in Lorca. We have obtained a partly bilateral rupture propagating to WSW (238A degrees, 54A degrees, 59A degrees) with 27 cm of maximum slip and shallow focus (4 km). The fault plane orientation corresponds to that of the Cejo de los Enamorados Fault located NE of the Lorca town and parallel to the Alhama de Murcia Fault. The distribution of slip on the fault plane can explain the lack of any observed surface rupture as we found that the rupture started at 4-km depth along a plane dipping at 54A degrees, with motion propagating upward to stop at 1.5 km below the surface. The strong motion and GPS data recorded near the epicenter are in agreement with the maximum slip on the fault. Directivity effects and the extreme shallowness of the rupture could explain the considerable damage that the earthquake caused in the town of Lorca.},
  language  = {en}
}
@article{CescaGrigoliHeimannetal.2014,
  author    = {Cesca, Simone and Grigoli, Francesco and Heimann, Sebastian and Gonzalez, Alvaro and Buforn, Elisa and Maghsoudi, Samira and Blanch, Estefania and Dahm, Torsten},
  title     = {The 2013 September-October seismic sequence offshore Spain: a case of seismicity triggered by gas injection?},
  series = {Geophysical journal international},
  volume    = {198},
  journal   = {Geophysical journal international},
  number    = {2},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0956-540X},
  doi       = {10.1093/gji/ggu172},
  pages     = {941 -- 953},
  year      = {2014},
  abstract  = {A spatially localized seismic sequence originated few tens of kilometres offshore the Mediterranean coast of Spain, close to the Ebro river delta, starting on 2013 September 5, and lasting at least until 2013 October. The sequence culminated in a maximal moment magnitude M-w 4.3 earthquake, on 2013 October 1. The most relevant seismogenic feature in the area is the Fosa de Amposta fault system, which includes different strands mapped at different distances to the coast, with a general NE-SW orientation, roughly parallel to the coastline. However, no significant known historical seismicity has involved this fault system in the past. The epicentral region is also located near the offshore platform of the Castor project, where gas is conducted through a pipeline from mainland and where it was recently injected in a depleted oil reservoir, at about 2 km depth. We analyse the temporal evolution of the seismic sequence and use full waveform techniques to derive absolute and relative locations, estimate depths and focal mechanisms for the largest events in the sequence (with magnitude mbLg larger than 3), and compare them to a previous event (2012 April 8, mbLg 3.3) taking place in the same region prior to the gas injection. Moment tensor inversion results show that the overall seismicity in this sequence is characterized by oblique mechanisms with a normal fault component, with a 30A degrees low-dip angle plane oriented NNE-SSW and a subvertical plane oriented NW-SE. The combined analysis of hypocentral location and focal mechanisms could indicate that the seismic sequence corresponds to rupture processes along shallow low-dip surfaces, which could have been triggered by the gas injection in the reservoir, and excludes the activation of the Amposta fault, as its known orientation is inconsistent with focal mechanism results. An alternative scenario includes the iterated triggering of a system of steep faults oriented NW-SE, which were identified by prior marine seismics investigations.},
  language  = {en}
}
@article{delFresnoDominguezCerdenaCescaetal.2015,
  author    = {del Fresno, Carmen and Dominguez Cerdena, Itahiza and Cesca, Simone and Buforn, Elisa},
  title     = {The 8 October 2011 Earthquake at El Hierro (M-w 4.0): Focal Mechanisms of the Mainshock and Its Foreshocks},
  series = {Bulletin of the Seismological Society of America},
  volume    = {105},
  journal   = {Bulletin of the Seismological Society of America},
  number    = {1},
  publisher = {Seismological Society of America},
  address   = {Albany},
  issn      = {0037-1106},
  doi       = {10.1785/0120140151},
  pages     = {330 -- 340},
  year      = {2015},
  abstract  = {We have studied the focal mechanism of an M-w 4.0 earthquake that occurred on 8 October 2011 in the southwest of El Hierro (Canary Islands), the largest shock of the swarm that preceded the submarine eruption of El Hierro 2011-2012. The joint focal mechanism solution of 34 foreshocks has also been obtained. The results for the mainshock are consistent with a pure double-couple mechanism of a strike-slip motion with a reverse component and a focal depth of 12-13 km. The stress pattern obtained from the focal mechanism indicates horizontal compression in a north-northwest-south-southeast direction, parallel to the southern ridge of the island, and a quasi-horizontal extension in an east-west direction. Similar stress pattern is derived from the joint solution of the foreshocks. The occurrence of this family of earthquakes at the moment of the maximum strain rate of the pre-eruptive swarm suggests that their rupture process is related to tectonic stress, which led to the eruption only two days later, 5 km away from the mainshock epicenter.},
  language  = {en}
}