scholarly journals Character of the Caribbean–Gônave–North America plate boundaries in the upper mantle based on shear‐wave splitting

2012 ◽  
Vol 39 (24) ◽  
Author(s):  
B. Benford ◽  
B. Tikoff ◽  
C. DeMets
Keyword(s):  
North America ◽  
Shear Wave ◽  
Upper Mantle ◽  
Shear Wave Splitting ◽  
Plate Boundaries ◽  
Wave Splitting ◽  
The Caribbean

Upper Mantle deformation patterns beneath norteast India from Shear-wave splitting analysis

2020 ◽  
Author(s):  
Jyotima Kanaujia ◽  
Ganpat Surve ◽  
Nava Hazarika
Keyword(s):  
Shear Wave ◽  
Upper Mantle ◽  
Plate Boundary ◽  
Shear Wave Splitting ◽  
Northeast India ◽  
Bengal Basin ◽  
Plate Boundaries ◽  
Shillong Plateau ◽  
Crust And Upper Mantle ◽  
Wave Splitting

<p>Telesesimic earthquake data recorded at eight seismograph stations across the northeast India are analysed for shear-wave splitting from core-refracted XKS phases (collectively PKS, SKS and SKKS). Shear-wave splitting parameters, derived from the analysis provide information about seismic anisotropy and deformation of the crust and upper mantle beneath each seismograph stations site. The results point towards the presence of complex and highly anisotropic crust and upper mantle beneath northeast India. Being surrounded by two seismically active plate boundaries, to the north by India-Eurasia collision plate boundary and to the east by Indo-Burman subduction plate boundary, the crust and upper mantle beneath the northeast India has been assumed to have complex deformation pattern. This present study provides an evidence for this assumption. According to station locations, we have one station BONG situated near the Main boundary thrust (at India-Eurasia collision zone), one station NAMS and eastern syntexis Himalaya, five station AZWL, SILS, DIPH and NKCR at Indo-Burman subduction plate boundary, one station SHLS and Shillong plateau bounded by Oldham Fault, Dauki Fault and Kopli fault, and one station AGAR at the boundary of Bengal basin. The direction of anisotropy is nearly E-W at BONG, NE-SW in the Indo-Burman subduction zone, nearly N-S on Shillong plateau and NW-SE at eastern syntexis of Himalaya. Source of anisotropy in the Himalaya collision boundary is result of lithospheric deformation due to finite strain induced by collision. In Shillong plateau and Indo-burman subduction boundary, source of anisotropy seems to be the asthenospheric flow-related strain which is also in harmony with the absolute plate motion (APM) of the Indian plate in a no net reference frame.</p>

Seismic anisotropy of the crust and upper mantle beneath western Tibet revealed by shear wave splitting measurements

2018 ◽  
Vol 216 (1) ◽  
pp. 535-544 ◽  
Author(s):  
Changhui Ju ◽  
Junmeng Zhao ◽  
Ning Huang ◽  
Qiang Xu ◽  
Hongbing Liu
Keyword(s):  
Shear Wave ◽  
Upper Mantle ◽  
Seismic Anisotropy ◽  
Shear Wave Splitting ◽  
Crust And Upper Mantle ◽  
Wave Splitting

scholarly journals Relation of crustal and upper mantle deformation beneath Sunda-Banda Island Arc inferred from shear-wave splitting analysis

2019 ◽  
Vol 1204 ◽  
pp. 012069
Author(s):  
Syuhada Syuhada ◽  
Nanang Tyasbudi Puspito ◽  
Titi Anggono ◽  
Nugroho Dwi Hananto ◽  
Hendra Grandis ◽  
...  
Keyword(s):  
Shear Wave ◽  
Upper Mantle ◽  
Shear Wave Splitting ◽  
Island Arc ◽  
Wave Splitting

Shear wave splitting as diagnostics of variable tectonic fabrics across the Eastern Alps – Bohemian Massif contact zone

2020 ◽  
Author(s):  
Luděk Vecsey ◽  
Jaroslava Plomerová ◽  
Vladislav Babuška ◽  
the AlpArray-EASI Working Group ◽  
the AlpArray Working Group
Keyword(s):  
Shear Wave ◽  
Bohemian Massif ◽  
Upper Mantle ◽  
Large Scale ◽  
Broad Band ◽  
Eastern Alps ◽  
Shear Wave Splitting ◽  
Splitting Methods ◽  
Mantle Lithosphere ◽  
Wave Splitting

<p>We examine lateral variations of shear-wave splitting evaluated from data recorded during the passive seismic experiments AlpArray-EASI (2014-2015) and AlpArray Seismic Network (2016-2019). The swath about 200 km broad and 540 km long along 13.3° E longitude was selected to study the large-scale anisotropy in the mantle lithosphere beneath the Bohemian Massif (BM) and the Eastern Alps. The region is covered by about 200 broad-band temporary and permanent stations.</p><p>The shear-wave splitting evaluation consists of several steps: it starts by automated identification and pre-processing of SKS waveforms, filtering and quality check. Then we analyse and, if needed, also correct seismic waveforms for seismometer mis-orientations of all stations used. To improve results of splitting analysis of signals distorted by noise, we carefully apply two splitting methods (eigenvalue, transverse energy). We stack splitting measurements for waves closely propagating within the upper mantle and include particle motion analysis. The modified version of the splitting methods (Vecsey et al., 2008) enables us to retrieve 3-D orientation of large-scale anisotropic structures in the mantle lithosphere and deformations within the sub-lithospheric part of the upper mantle.</p><p>Both the evaluated shear-wave splitting parameters and the particle motions are consistent within sub-regions of the Alpine and BM upper mantle and exhibit significant and often sudden lateral changes across the whole region. We relate such changes to sharply bounded anisotropic domains with uniform fossil fabrics in the mantle lithosphere.</p>

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