Using the receiver function for studying earth deep structure in the Southern Borborema Province

2019 ◽  
Vol 94 ◽  
pp. 102221
Author(s):  
Chris B. Fianco ◽  
George Sand França ◽  
Diogo Farrapo Albuquerque ◽  
Carlos da Silva Vilar ◽  
Roberto Max Argollo
Keyword(s):  
Deep Structure ◽  
Receiver Function ◽  
Borborema Province

scholarly journals Lithospheric and sublithospheric deformation under the Borborema Province of northeastern Brazil from receiver function harmonic stripping

Solid Earth ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 893-905 ◽  
Author(s):  
Gaelle Lamarque ◽  
Jordi Julià
Keyword(s):  
Lithospheric Mantle ◽  
Seismic Anisotropy ◽  
Receiver Function ◽  
Seismic Station ◽  
Atlantic Coast ◽  
Shear Zones ◽  
Receiver Functions ◽  
Azimuthal Anisotropy ◽  
Northeastern Brazil ◽  
Borborema Province

Abstract. The depth-dependent anisotropic structure of the lithosphere under the Borborema Province in northeast Brazil has been investigated via harmonic stripping of receiver functions developed at 39 stations in the region. This method retrieves the first (k=1) and second (k=2) degree harmonics of a receiver function dataset, which characterize seismic anisotropy beneath a seismic station. Anisotropic fabrics are in turn directly related to the deformation of the lithosphere from past and current tectonic processes. Our results reveal the presence of anisotropy within the crust and the lithospheric mantle throughout the entire province. Most stations in the continental interior report consistent anisotropic orientations in the crust and lithospheric mantle, suggesting a dominant northeast–southwest pervasive deformation along lithospheric-scale shear zones developed during the Brasiliano–Pan-African orogeny. Several stations aligned along a northeast–southwest trend located above the (now aborted) Mesozoic Cariri–Potiguar rift display large uncertainties for the fast-axis direction. This non-azimuthal anisotropy may be related to a complex anisotropic fabric resulting from a combination of deformation along the ancient collision between Precambrian blocks, Mesozoic extension and thermomechanical erosion dragging by sublithospheric flow. Finally, several stations along the Atlantic coast reveal depth-dependent anisotropic orientations roughly (sub)perpendicular to the margin. These results suggest a more recent overprint, probably related to the presence of frozen anisotropy in the lithosphere due to stretching and rifting during the opening of the South Atlantic.

2D velocity profiles along south- and northwestern Norway: An approach using receiver function analysis and Markov chains

2020 ◽  
Author(s):  
Marco Brönner ◽  
Claudia Pavez
Keyword(s):  
Deep Structure ◽  
Receiver Function ◽  
Function Analysis ◽  
Velocity Model ◽  
Reversible Jump ◽  
Moho Discontinuity ◽  
Mantle Transition Zone ◽  
Temporary Network ◽  
Receiver Function Analysis ◽  
Teleseismic Events

<p>A receiver function analysis was carried out along two profiles located in north- and southwestern Norway. We selected and processed 801 teleseismic events registered by twelve seismic stations belonging to the 2002-2005 Geofon/Aarhus temporary network. The HK (depth vs Vp/Vs) stacking procedure and a Reversible jump Markov chain Monte Carlo (Rj-McMC) inversion were applied independently with the objective to reveal new crustal and crust-mantle transitional contrasts gaining a better understanding of the geology. In the southern profile, the most noticeable feature corresponds to a Moho offset of about ~5 km ca. 85 km to the east of the Norwegian coast: That feature was previously observed in several occasions and is also well-supported from this research. Furthermore, a very deep Moho discontinuity – at between 45 – 50 km depth - was found beneath the northern profile, approximately 70 km inland from the coast, and dipping about 30° to the northwest. Even when this deep structure was previously inferred through other methods, its presence was not certainly confirmed and so far, the origin of this feature is still disputed. We discuss two hypotheses, which are valid to explain the occurrence of the noticeable anomaly. First, a gradual and wide crust-mantle transition zone, which is also reflected in the velocity model or second, the presence of a paleo-slab of Fennoscandian basement subducted and deformed during the Caledonian Orogen (490-390 Ma).</p>

A study on deep structure using teleseismic receiver function in Western Yunnan

2004 ◽  
Vol 17 (3) ◽  
pp. 262-271 ◽  
Author(s):  
Chuan-song He ◽  
Chun-yong Wang ◽  
Jian-ping Wu
Keyword(s):  
Deep Structure ◽  
Receiver Function ◽  
Western Yunnan ◽  
Teleseismic Receiver Function

Deep structure of a stretched lithosphere: Magnetotelluric imaging of the southeastern Borborema province, NE Brazil

2014 ◽  
Vol 610 ◽  
pp. 39-50 ◽  
Author(s):  
Andrea C.L. Santos ◽  
Antonio L. Padilha ◽  
Reinhardt A. Fuck ◽  
Augusto C.B. Pires ◽  
Icaro Vitorello ◽  
...  
Keyword(s):  
Deep Structure ◽  
Borborema Province ◽  
Magnetotelluric Imaging

scholarly journals Localized foundering of Indian lower crust in the India–Tibet collision zone

2020 ◽  
Vol 117 (40) ◽  
pp. 24742-24747
Author(s):  
Danian Shi ◽  
Simon L. Klemperer ◽  
Jianyu Shi ◽  
Zhenhan Wu ◽  
Wenjin Zhao
Keyword(s):  
Lower Crust ◽  
Gravitational Instability ◽  
Deep Structure ◽  
Receiver Function ◽  
Gravity Data ◽  
Normal Faults ◽  
Satellite Gravity ◽  
Crust And Upper Mantle ◽  
Collision Zone ◽  
Dehydration Reactions

The deep structure of the continental collision between India and Asia and whether India’s lower crust is underplated beneath Tibet or subducted into the mantle remain controversial. It is also unknown whether the active normal faults that facilitate orogen-parallel extension of Tibetan upper crust continue into the lower crust and upper mantle. Our receiver-function images collected parallel to the India–Tibet collision zone show the 20-km-thick Indian lower crust that underplates Tibet at 88.5–92°E beneath the Yarlung-Zangbo suture is essentially absent in the vicinity of the Cona-Sangri and Pumqu-Xainza grabens, demonstrating a clear link between upper-crustal and lower-crustal thinning. Satellite gravity data that covary with the thickness of Indian lower crust are consistent with the lower crust being only ∼30% eclogitized so gravitationally stable. Deep earthquakes coincide with Moho offsets and with lateral thinning of the Indian lower crust near the bottom of the partially eclogitized Indian lower crust, suggesting the Indian lower crust is locally foundering or stoping into the mantle. Loss of Indian lower crust by these means implies gravitational instability that can result from localized rapid eclogitization enabled by dehydration reactions in weakly hydrous mafic granulites or by volatile-rich asthenospheric upwelling directly beneath the two grabens. We propose that two competing processes, plateau formation by underplating and continental loss by foundering or stoping, are simultaneously operating beneath the collision zone.

Upper-lower crust thickness of the Borborema Province, NE Brazil, using Receiver Function

2013 ◽  
Vol 42 ◽  
pp. 242-249 ◽  
Author(s):  
Cesar Garcia Pavão ◽  
George Sand França ◽  
Marcelo Bianchi ◽  
Tati de Almeida ◽  
Mônica G. Von Huelsen
Keyword(s):  
Lower Crust ◽  
Receiver Function ◽  
Borborema Province ◽  
Crust Thickness

scholarly journals Structural Characteristics of Moho Surface Based on Time Series Function of Natural Earthquakes

2021 ◽  
Vol 13 (4) ◽  
pp. 763
Author(s):  
Xuelei Li ◽  
Zhuo Jia ◽  
Nanqiao Du ◽  
Yi Xu ◽  
Gongbo Zhang
Keyword(s):  
Seismic Wave ◽  
Velocity Structure ◽  
Deep Structure ◽  
Receiver Function ◽  
Structural Characteristics ◽  
Velocity Ratio ◽  
Tectonic Activity ◽  
Volcanic Area ◽  
Long Distance ◽  
Reflection Characteristics

Remote sensing is a non-contact, long-distance detection technology. The reflection characteristics of a seismic wave can be used to detect remote and non-contact targets. Based on the reflection characteristics of a seismic wave, the underground structure in Tengchong Volcanic Area is explored. In order to further study the deep structure and magmatic activity of the crust in the volcanic area, we carried out a one-year mobile seismic observation. In this paper, nine broadband seismic stations were set up in the Tengchong Volcanic Area, and 3350 receiver function waveforms were collected. The crustal thickness, average wave velocity ratio, and Poisson’s ratio below these stations were calculated by the receiver function method, and the velocity structure near the Moho below these stations was evaluated. Combined with topographic data from SRTM3 (Shuttle Radar Topography Mission 3), this study reveals the dynamic relationship among crustal structure, crustal magmatism, and regional tectonic movement. Mantle upwelling plays an important role on the Moho uplift in the northern Tengchong Volcanic Area, and there are interconnected intracrustal magma chambers in the upper platform. The evaluation results of the Moho transition zone also indicate that the Dayingjiang fault is closely related to the tectonic activity of the Tengchong Volcanic fault.

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