Tracking regional heterogeneities through seismic ambient noise constrains: What Rayleigh wave tomography can tell about deep structures in northern Morocco

Fellah, Younes El; Bouskri, Ghizlane; Harnafi, M.; el-aal, Abd el-aziz Khairy Abd; Timoulali, Youssef; Ouchen, Ibrahim; Azguet, Roumaissae

doi:10.1016/j.jafrearsci.2019.103615

Cited by 6 publications

(2 citation statements)

References 34 publications

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“…Regarding the Rif and Tell ranges, The estimated crustal thickness beneath the Rif cordillera ranged from a maximum of 45/50 km to a minimum of 30 km at the border with the southern portion of the Alboran Sea (De Lis Mancilla et al, 2012). This domain is distinguished by deep sedimentary, which is the result of complex tectonic movements (Chalouan et al, 2008;El Fellah et al, 2019). It consists of three primary structural domains: During the 1994-2019 period, three catastrophic earthquakes occurred in the Rif region near Al Hoceima city on January 25, 2016 (Mw 6.3), February 24, 2004 (M w 6.4), and May 26, 1994 (M w 6.0) (Arab et al, 2020).…”

Section: Seismotectonic Settingmentioning

confidence: 99%

Estimation of Seismic Kappa Parameter and Near-Surface Attenuation in Morocco

Boulanouar¹,

Rahmouni²,

Zian³

et al. 2022

Ecol. Eng. Environ. Technol.

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The goal of this study is to estimate the kappa (κ) parameter for a group of 12 broadband stations, located in different geological structures in Morocco, a country with moderate seismic activity. In this study, the kappa, κ has been obtained from the spectral analysis of the shear waves of 42 earthquakes, recorded in Morocco. Using 321 seismograms recorded in the period between 2009 and 2012 by the Picasso Project, the average κ-values have been computed from the horizontal components. For each station, the relationship between κ values and the hypocentral distance was determined. We separately investigated and studied the distance dependence of the stations located on soft soil and hard rock sites. The estimated average factor of the κ value ranges from 0.0682 for the hard sites to 0.0763 for the soft sites, with 0.072 as an average value. The lack of a significant correlation found between κ and magnitude at all stations considered in this study suggests that kappa is mainly dependent on local site characteristics. To the best of our knowledge, no studies related to kappa parameter estimation have been published for this region. The results generated in this study can be used for the seismic hazard evaluation of Morocco.

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Section: Seismotectonic Settingmentioning

confidence: 99%

Estimation of Seismic Kappa Parameter and Near-Surface Attenuation in Morocco

Boulanouar¹,

Rahmouni²,

Zian³

et al. 2022

Ecol. Eng. Environ. Technol.

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“…Such studies have been conducted to investigate the local crustal structure and better understand the geological and tectonic processes that have shaped the region [Gil et al, 2014;Mancilla and Diaz, 2015;Timoulali et al, 2014aTimoulali et al, , 2022. These studies use various geophysical techniques, such as seismic reflection and refraction, seismic/electrical tomography, magnetic surveys, and stations measurements to map the subsurface structure as well as the basins geometry [for Deep Seismic Sounding in the Alboran Sea 1974Sea , 1978Gurrria and Mezcua, 2000;Timoulali et al, 2014;El Fellah et al, 2019;EL Hilali et al, 2021;Taj et al, 2024]. The crust thickness beneath the Betic Cordillera in Southern Spain is estimated to be around 35-38 km.…”

Section: Introductionmentioning

confidence: 99%

Crustal Attenuation Tomographic Image of Northern Morocco: Indication of High Tectonic Activities

Najim,

El Hilali,

Timoulali

et al. 2024

Annals of Geophysics

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Northern Morocco is known by its complex tectonic activity and has been the subject of various geophysical and geodynamic studies aimed to understand the physical properties and composition of the Earth’s crust and upper mantle. The waveforms of earthquakes recorded by the Topo – Iberia – Picasso seismic networks from 2008 to 2012 are analyzed to determine the decay properties of the coda wave and map the attenuation and absorption properties of the crust in this region. The coda quality factor Qc was estimated in five non‑overlapping frequency windows, ranging from 1.5 to 24 Hz, using recordings of local earthquakes. The measurements of Qc were then used to create maps of the absorption quality factor (Qi) using a linearized approximation. These maps were compared with the tectonic settings of the region to gain further insight into the crustal properties. Lateral and vertical variations of the coda quality factor (Qc) were investigated by creating a three‑dimensional tomographic image of the region. The results showed strong lateral variations of absorption in the northern part of Morocco, indicating high tectonic activity. Areas with high tectonic activity and high absorption were characterized by low values of Qc, while areas with low tectonic activity and low absorption had high values of Qc. The areas with thick cover sedimentary materials and shallow geothermal activity showed low‑frequency absorption. When compared to previous studies in northern Morocco, the study provides new information about the three‑dimensional attenuation model of the Earth’s crust.

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