[J03-P] Poster

[J03-P-03] The topography of the lithosphere-asthenosphere boundary beneath the Korean Peninsula from S receiver functions

^○Sang-Hyun Lee¹, Junkee Rhie¹, Tae-Seob Kang², Seongryong Kim¹, Hyun Jae Yoo², Won Sang Lee³, Yongcheol Park³ (1.Seoul National University, Seoul, Korea, 2.Pukyong National University, Busan, Korea, 3.Korea Polar Research Institute, Incheon, Korea)

The topography of the lithosphere-asthenosphere boundary (LAB) beneath the Korean Peninsula was determined using teleseismic S-receiver functions, obtained from the seismographs in Korea from 2005 to 2012. The receiver functions were migrated from the delayed time to the corresponding conversion points (CCP) of S-to-p phases using the IASP91 model and stacked with the common conversion points in circular bin. The LAB beneath the Korean Peninsula was determined at a depth range of 60 - 100 km from the CCP stacked receiver functions. The LAB depth is deep at the north and getting shallow to the south with a rapid change along the tectonic boundary between the Gyeonggi Massif and the Okcheon Fold Belt. This shallow LAB, considering the Precambrian bedrock of the Korean Peninsula, implies the lithosphere thinning accompanied by the coeval subduction of the paleo-Pacific plate since the Jurassic. The northward subduction of the oceanic plate from the southeast in the Jurassic could result in the northward dipping of the LAB depth beneath the Korean Peninsula. The structure in the uppermost mantle reflects the complex tectonic history surrounding the Korean Peninsula. Therefore, the LAB topography reveled in this study would contribute to understand the tectonic history of the Korean Peninsula.