Mantle dynamics beneath Greece from SKS and PKS seismic anisotropy study

Acta Geophysica

George Drakatos¹  Ioannis Fountoulakis²  Ioannis Spingos²  Christos Millas²  George Kaviris²  Panayotis Papadimitriou² 

[1] National Observatory of Athens;National and Kapodistrian University of Athens

关键词: Shear-wave splitting;    Tear;    Hellenic Subduction Zone;    Mantle wedge;   

DOI  :  10.1007/s11600-018-0225-z

学科分类：地球科学(综合)

来源: Polska Akademia Nauk * Instytut Geofizyki

【 摘 要 】

SKS and PKS splitting parameters were determined in the broader Greek region using data from 45 stations of the Hellenic Unified Seismological Network and the Kandilli Observatory and Earthquake Research Institute, utilizing teleseismic events that occurred between 2010 and 2017. Data were processed for shear-wave splitting with the Minimum Energy Method that was considered the optimal. The results generally confirm the existence of anisotropic zonation in the Hellenic subduction system, with alternating trench-normal and trench-parallel directions. The zonation is attributed to the upper and lower olivine fabric layers that can, potentially, be present in the subduction zone. At the edges of this zone, two possible toroidal flow cases have been identified, implying the existence of tears that allow the inflow of asthenospheric material in the mantle wedge. The high number of null measurements in the KZN and XOR stations indicates a possible anisotropic transition zone between the fore-arc and back-arc areas. SKS and PKS splitting results are jointly interpreted, given that they yield similar values in most cases.

【 授权许可】

Unknown