[S-CG39] Science of slow earthquakes: Toward unified understandings of whole earthquake process

[SCG39-P27] Lithosphere properties along North-Central Chile subduction region and Relation to slow slip

*POUSALI MUKHERJEE¹、Yoshihiro Ito¹、Emmanuel Soliman M. Garcia¹、Kajaljyoti Borah² (1.Disaster Prevention Research Institute, Kyoto University、2.Indian Institute of Science Education and Research, Kolkata)

キーワード：Receiver Function, Chile Subduction System, Vs and Vp/Vs ratio, Lithosphere, Slow slip

The Chile region in South America is one of the most active tectonic regions where the Nazca plate subducts beneath the South American plate. In addition to megathrust earthquakes, the region has also been reported to host slow slip earthquakes from shallow subsurface to deeper portions. Investigating the lithosphere of the slow slip and non slow slip area in Chile subduction zone is crucial in understanding the role of the internal structure to control slow slip. In this study, we are using teleseismic receiver function method to estimate the lithospheric parameters in northern and central Chile using in an around the slow slip region to estimate the shear wave velocity variation and the Vp/Vs ratio. The Vs and the Vp/Vs ratio is sensitive to the fluid distribution in the lithosphere. The results show differences in lithosphere properties in the continental and subducted oceanic lithosphere, indicating that they could have played a key role in occurrence of past slow slips in the region.