Paleoseismology of the Yangsan Fault, southeastern part of the Korean Peninsula

• Main Author: J. B. Kyung
• Format: Article
• Language: English
• Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 2003-06-01
• Series: Annals of Geophysics
• Subjects: Yangsan Fault (YSF); Korean Peninsula; averge slip rate; most recent event
• Online Access: http://www.annalsofgeophysics.eu/index.php/annals/article/view/3465

The NNE-trending Yangsan Fault (YSF) is the most prominent fault in the southeastern part of the Korean Peninsula
 and has a continuous trace about 200 km long. Activity on this fault was recently investigated using aerial
 photographs, topographic analysis, and trenching. The geomorphologic evidence of Late Quaternary faulting is
 clearly recognized on both the northern (Yugyeri and Tosung-ri areas) and southern parts (Eonyang to Tongdosa
 area) of the fault. The main YSF is marked by a zone of shattered rock that is tens of meters wide and zone of fault
 gouge. During the Late Quaternary, right-lateral movement occurred mainly on the southern part, as shown by lowangle
 striations on the fault plane, elongation of deformation features in the fault gouge. The estimated vertical slip
 rate is about 0.02-0.07 mm/yr, and the lateral slip rate may be several times larger than the vertical rate. The most
 recent event occurred prior to deposition of Holocene alluvium. In the northern part, the fault locally changes trend
 to almost N-S, dips to the east and has reverse movement. The average vertical slip rate is estimated less than
 0.1 mm/yr. The most recent event probably occurred after 1314 cal. years BP (A.D. 536).