Statistical features of the 2010 Beni-Ilmane, Algeria, aftershock sequence

The aftershock sequence of the 2010 Beni-Ilmane (MW 5.5) earthquake is studied in depth to analyze the spatial and temporal variability of seismicity parameters of the relationships modeling the sequence. The b value of the frequency–magnitude distribution is examined rigorously. A threshold magnitu...

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Detalles Bibliográficos
Autores: Hamdache, M., Peláez, J.A., Gospodinov, D., Henares, J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Universidad de Jaén
Repositorio:RUJA. Repositorio Institucional de la Producción Científica de la Universidad de Jaén
OAI Identifier:oai:ruja.ujaen.es:10953/6861
Acceso en línea:https://doi.org/10.1007/s00024-017-1708-6
https://hdl.handle.net/10953/6861
Access Level:acceso abierto
Palabra clave:Aftershock sequence
Stochastic point process
RETAS model
ETAS model
Fractal dimension
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Descripción
Sumario:The aftershock sequence of the 2010 Beni-Ilmane (MW 5.5) earthquake is studied in depth to analyze the spatial and temporal variability of seismicity parameters of the relationships modeling the sequence. The b value of the frequency–magnitude distribution is examined rigorously. A threshold magnitude of completeness equal to 2.1, using the maximum curvature procedure or the changing point algorithm, and a b value equal to 0.96 ± 0.03 have been obtained for the entire sequence. Two clusters have been identified and characterized by their faulting type, exhibiting b values equal to 0.99 ± 0.05 and 1.04 ± 0.05. Additionally, the temporal decay of the aftershock sequence was examined using a stochastic point process. The analysis was done through the restricted epidemic-type aftershock sequence (RETAS) stochastic model, which allows the possibility to recognize the prevailing clustering pattern of the relaxation process in the examined area. The analysis selected the epidemic-type aftershock sequence (ETAS) model to offer the most appropriate description of the temporal distribution, which presumes that all events in the sequence can cause secondary aftershocks. Finally, the fractal dimensions are estimated using the integral correlation. The obtained D2 values are 2.15 ± 0.01, 2.23 ± 0.01 and 2.17 ± 0.02 for the entire sequence, and for the first and second cluster, respectively. An analysis of the temporal evolution of the fractal dimensions D-2, D0, D2 and the spectral slope has been also performed to derive and characterize the different clusters included in the sequence.