Mantle flow in the South Sandwich subduction environment from source-side shear wave splitting
[1] The occurrence of seismic anisotropy in the Earth’s upper mantle is a global phenomenon related to subcrustal deformation and flow processes. The shear wave splitting analysis method has led to a global set of anisotropy maps mainly derived from receiver-side analysis. Remote places with few sei...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.464.9742 http://epic.awi.de/17968/1/Mll2007f.pdf |
| Summary: | [1] The occurrence of seismic anisotropy in the Earth’s upper mantle is a global phenomenon related to subcrustal deformation and flow processes. The shear wave splitting analysis method has led to a global set of anisotropy maps mainly derived from receiver-side analysis. Remote places with few seismometers deployed remain unexamined. Source-side splitting analysis allows mapping of mantle fabrics in these regions. Here, we investigate seismic anisotropy in the South Sandwich Islands subduction environment. Core-reflected ScS waves recorded at the Neumayer seismograph network are corrected for well constrained receiver anisotropy and then analysed for source anisotropy. Sub-slab mantle minerals are aligned horizontally almost parallel to the trench indicating awestward flow around the subducting slab. This is consistent with a model of horizontal mantle flow due to slab rollback that was previously inferred from marine and geochemical studies in the back-arc |
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