Receiver function images of subducted slabs beneath South Korea

We analyzed stacking receiver functions using 1162 events observed on 39 broadband seismic stations in South Korea. To make receiver function images a grid was set 0.25 degrees between 30.0°N and 41.0°N in latitude and 120°E and 135°E in longitude, and piercing points of individual receiver functions were computed for a 5 km depth interval from 5 km to 800 km in depth. Individual receiver functions were converted to depth and laterally migrated to their conversion point using the iasp91 model with redundant signals stacked to enhance signal. Our P-wave receiver function images show clear P to S conversions on boundaries created by the slabs subducting from the Kurile, Japan, Izu-Bonin, and Mariana arcs, the northern Kurile and Mariana slabs beneath the Korean Peninsula. Depressed 660-km (P660s) conversion phases are observed beneath eastern part of South Korea and the East See between 128°E and 133°E in longitude indicating that the cold slab penetrates the 660-km seismic discontinuity in this region.