Archaeoseismological studies on historical heritage sites in the Gyeongju area, SE Korea

作者：Jin, Kwangmin; Lee, Minjung; Kim, Young-Seog; Choi, Jeong-Heon

来源：Quaternary International, 2011, 242(1): 158-170.

DOI：10.1016/j.quaint.2011.03.055

• MARINE TERRACE SEDIMENTS
• ARCHAEOLOGICAL SITES
• FAULT
• EARTHQUAKES
• SEISMICITY
• DISPLACEMENT
• MAGNITUDE
• CORINTH
• RATES
• GULF

Recently, a fallen Buddha statue of the late-8th century was discovered in Mt. Nam, Gyeongju, SE Korea. The Gyeongju area is located in intersection of two major young structural features in Korea: the Yangsan and Ulsan faults. According to historical records, such as the ancient texts of Samguksagi. Chaljubongi, and Mulcseojipyeon, the studied area was significantly affected by several large earthquakes of MM Intensity = VII and estimated magnitude up to M-L = 6.7, such as the destructive events occurred in 768 AD, 779 AD and 1036 AD. Especially, the last two earthquakes are historically well documented as triggering severe damages in other historical buildings (Hwangryongsa pagoda and Bulguksa temple) around the area. This paper examines the potential connection between the fallen Buddha statue and any of the large historical earthquakes documented in the area. Restoration study of the original position of the fallen Buddha statue, based on fracture analysis, indicates that the fallen Buddha statue rotated 20 degrees clockwise and slid a few meters from its original position during a large rockfall event. Preliminary OSL dating was carried out from weathered soil below a large granite block adjacent to the fallen statue. The age of 0.76 +/- 0.12 ka indicates a bracketed time-period between the years 1130 and 1370 AD for the statue fall. However, no earthquake is reported for this time-period in the area. Although the available data does not exactly indicate any specific earthquake, based on the historic records, artistic styles, differential weathering of the statue, OSL dating and nearby historically documented archaeoseismic damage, the 1036 AD earthquake (M-L = 6.4) is proposed as the more likely event responsible for the studied damage. Furthermore, other earthquake damage to historic heritage sites was also reported in historical records around the study area. Therefore, a future seismic hazard study should be carried out to preserve the important national heritage sites in this area. The combination of paleoseismological and archaeoseismological studies is essential to estimate potential earthquake hazard in this area.

• 出版日期2011-10-1