JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

S (Solid Earth Sciences) » S-SS Seismology

[S-SS04] [EE] Subduction zone dynamics from regular earthquakes through slow earthquakes to creep

Wed. May 24, 2017 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall HALL7)

convener:Kyuichi Kanagawa(Graduate School of Science, Chiba University), Kazushige Obara(Earthquake Research Institute, The University of Tokyo), Demian M Saffer(Pennsylvania State University), Laura Wallace(University of Texas Institute for Geophysics)

[SSS04-P49] Sub-slab anisotropy in the western Pacific :
The Izu-Bonin and Mariana regions

*Li-Chen Hsu1, Cheng-Chien Peng1, Ban-Yuan Kuo2, Chin-Wu Chen1 (1.National Taiwan University, 2.Institute of Earth Sciences, Academia Sinica)

Understanding the mechanism of plate subduction helps us put together a whole picture of how the mantle works under plate tectonics. The sub-slab seismic anisotropy serves as a direct tool for illuminating subduction dynamics, implying the flow direction and deformation patterns of subducting slabs.
We measured source-side shear wave splitting with receiver-side correction for the Izu-Bonin and Mariana subduction zones. The initial results show that the deeper slab is associated with larger delay times (dt) in Izu-Bonin region, while delay times of deeper slab in the Mariana are smaller. The fast directions (f) of the two regions seem to be random with respect to the slab contour. However, anisotropy for shallow events in the Izu-Bonin slab is consistent with the relative plate motion. The next step is to consider the radial anisotropy in the receiver-side correction.