Active Fault Trace Identification Using a LiDAR High-Resolution DEM: A Case Study of the Central Yangsan Fault, Korea

Korea has been recognized as an earthquake-safe zone, but over recent decades, several earthquakes, at a medium scale or higher, have occurred in succession and around the major fault zones, hence there is need for studying active faults to mitigate earthquake risks. In Korea, research on challenging owing urbanization, high precipitation, erosion rates, relatively low activity compared countries plate boundaries. To overcome these difficulties, use of aerial light detection ranging (LiDAR) techniques providing high-resolution images digital elevation models (DEM) that filter vegetation cover introduced. Multiple outcrops reported along Yangsan Fault, which southeastern area Korean Peninsula. This study aimed detect by performing detailed topographic analysis LiDAR central segment Fault. The image covered 4.5 km 15 had average ground point density 3.5 points per m2, produced DEMs greater than 20 cm. Using DEMs, we identified 2–4 m scarp 50–150 deflected streams with dextral offset. Based analysis, further conducted trench field investigation successfully located cut Quaternary deposits. N–S NNE-striking surfaces unconsolidated deposits comprising nine units, observed slickenlines indicated reverse strike-slip. optically stimulated luminescence (OSL) age dating results indicate last 3200 years ago, one most