@misc{10481/93497,
year = {2024},
month = {5},
url = {https://hdl.handle.net/10481/93497},
abstract = {The Granada Basin is a slowly deforming intramountain basin in the Betic Cordillera (S-Spain). Despite historical
and paleoseismological evidence for M6 earthquakes, instrumental seismicity lacks large events and the seismotectonic
model must be built from small earthquakes (M < 5). Here, we reanalyze 35 years of data from the
Granada Basin short period network, and further seismic stations with shorter operating time, to identify seismogenic
structures and understand their relationships. We sort events with similar waveforms into multiplet
clusters and perform relative location to image active fault patches. Cluster orientations are used as a priori
constraint for inverting focal mechanisms from composite cluster polarity measurements. We further estimate
moment tensor solutions from full waveform inversion using local and regional broadband stations. We can
identify four groups of structures at different positions in the basin: 1) in the northeast sector, we observe
shallow, NW-SE striking, high-angle normal faulting, often related with known fault structures; 2) the southern
sector shows high-angle normal faulting on unmapped, ~E-W striking structures at mid-crustal depths; 3) between
both groups, we image sub-horizontal fault patches, associated with the basal detachment beneath the
basin, showing SSW transport direction; 4) at the western limit of the basin, we find ~N-S trending, left-lateral
strike-slip faults. Groups 2 and 3 are characterized by clusters with overall constant event production rate,
indicating ongoing and largely aseismic creep of the basal detachment over the last 35 years. Seismological
evidence suggests a locking depth of ~10 km and a brittle-ductile transition near 15 km, according to the depth
range of clusters in groups 2 and 3.},
abstract = {The Granada Basin is a slowly deforming intramountain basin in the Betic Cordillera (S-Spain). Despite historical
and paleoseismological evidence for M6 earthquakes, instrumental seismicity lacks large events and the seismotectonic
model must be built from small earthquakes (M < 5). Here, we reanalyze 35 years of data from the
Granada Basin short period network, and further seismic stations with shorter operating time, to identify seismogenic
structures and understand their relationships. We sort events with similar waveforms into multiplet
clusters and perform relative location to image active fault patches. Cluster orientations are used as a priori
constraint for inverting focal mechanisms from composite cluster polarity measurements. We further estimate
moment tensor solutions from full waveform inversion using local and regional broadband stations. We can
identify four groups of structures at different positions in the basin: 1) in the northeast sector, we observe
shallow, NW-SE striking, high-angle normal faulting, often related with known fault structures; 2) the southern
sector shows high-angle normal faulting on unmapped, ~E-W striking structures at mid-crustal depths; 3) between
both groups, we image sub-horizontal fault patches, associated with the basal detachment beneath the
basin, showing SSW transport direction; 4) at the western limit of the basin, we find ~N-S trending, left-lateral
strike-slip faults. Groups 2 and 3 are characterized by clusters with overall constant event production rate,
indicating ongoing and largely aseismic creep of the basal detachment over the last 35 years. Seismological
evidence suggests a locking depth of ~10 km and a brittle-ductile transition near 15 km, according to the depth
range of clusters in groups 2 and 3.},
organization = {Spanish Ministerio de Economía y Competitividad
(Project PID2019-109608GB-I00)},
organization = {Spanish Ministerio de Economía y Competitividad
(Project PID2019-109608GB-I00)},
organization = {Fondo Europeo de Desarrollo Regional,
FEDER)},
organization = {Fondo Europeo de Desarrollo Regional,
FEDER)},
organization = {plan propio University of Granada},
organization = {plan propio University of Granada},
organization = {program
(PPJIA2023-002)},
organization = {program
(PPJIA2023-002)},
organization = {CIEMAT and FEDER through the
Spanish Ministerio de Ciencia, Innovación y Universidades, ESFRI-2019-
02-CIEM-4 - DONES-PRIME, “Actividades de preparación del emplazamiento
de IFMIF-DONES e implantación de laboratorios relacionados
(2020-2023)”},
organization = {CIEMAT and FEDER through the
Spanish Ministerio de Ciencia, Innovación y Universidades, ESFRI-2019-
02-CIEM-4 - DONES-PRIME, “Actividades de preparación del emplazamiento
de IFMIF-DONES e implantación de laboratorios relacionados
(2020-2023)”},
organization = {Andalusian Conserjería de Economía, Innovación y Ciencia (Projects B-RNM-528-UGR20 and CEXP- 178-UGR23},
organization = {Andalusian Conserjería de Economía, Innovación y Ciencia (Projects B-RNM-528-UGR20 and CEXP- 178-UGR23},
publisher = {Elsevier},
keywords = {Seismotectonics},
keywords = {Seismotectonics},
keywords = {Multiplet relocation},
keywords = {Multiplet relocation},
keywords = {Moment tensor inversion},
keywords = {Moment tensor inversion},
title = {Seismogenic structures and active creep in the Granada Basin (S-Spain)},
doi = {10.1016/j.tecto.2024.230368},
author = {Stich, Daniel and Morales Soto, José and López Comino, José Ángel and Araque-Pérez, Carlos José and Azañón Hernández, José Miguel and Dengra, Miguel Ángel and Ruiz, Mario and Weber, Moisés},
}