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

• Published in: Journal of physics. Conference series 2019-04, Vol.1204 (1), p.12069
• Main Authors: Syuhada, Syuhada, Puspito, Nanang Tyasbudi, Anggono, Titi, Hananto, Nugroho Dwi, Grandis, Hendra, Yudistira, Tedi
• Format: Article
• Language: English
• Subjects: Broadband; Island arcs; Splitting; Subduction (geology); Tectonics
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1204/1/012069

We study the possible correlation of deformation in the crust and upper mantle beneath Sunda-Banda Island Arc using shear wave splitting analysis. The study area is very complex and located in the region where there is a transition in tectonic setting from subduction to collision. In this study, we measure the upper mantle splitting parameters from local events recorded at 6 broadband stations. The fast directions of the upper mantle splitting results are then compared with the orientation of fast waves previously obtained in the crust. Thus, this complex tectonic setting is expected to provide correlation of deformation pattern in the crust and upper mantle derived from the splitting results. The results show that the upper mantle fast orientations are generally parallel to the crustal splitting pattern. This finding suggests that this pattern could be caused the preferential alignment of anisotropic mineral inside the medium vertically localized in thin channel underneath the volcanic islands, or fracture zone fabrics related to the change of tectonic regime from subduction to collision, which involves high stresses and strains in the plate boundary.