Topography of the 410 and 660 km discontinuities beneath the Korean Peninsula and southwestern Japan using teleseismic receiver functions

摘要: Topography of the 410 and 660 km seismic upper mantle discontinuities beneath Korean Peninsula southwestern Japan were determined using teleseismic receiver functions. P functions migrated from delayed times to corresponding piercing (conversion) points P-to-S converted phases, one-dimensional (1-D) three-dimensional (3-D) models. Receiver then stacked Common Conversion Point (CCP) techniques, enhance signal-to-noise ratios thereby reduce uncertainty (noise). The clearly imaged, as positively valued amplitude peaks CCP in study area. Topographic variations roughly consistent with low temperature subducting Pacific Plate. However, complex structure Plate produced distinct changes discontinuities, which cannot be explained by alone. Depression discontinuity, observed a wide region extending Kyushu Island, may related trench rollback history. Furthermore, topography discontinuity varies significantly latitude. At latitudes higher than 38°N, its depth remains unchanged, despite presence stagnant slab, while significant depression has been at below 36°N. This have caused differences angles subduction slab Izu-Bonin slab. heterogeneity water content slabs also contributed this topographical difference.