추계학적 지진동 모사에서 유한단층 모델의 민감도 분석
Sensitivity Analysis of Finite Fault Model in Stochastic Ground Motion Simulations
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
Recent earthquakes in Korea, like Gyeongju and Pohang, have highlighted the need for accurate seismic hazard assessment. The lack of substantial ground motion data necessitates stochastic simulation methods, traditionally used with a simplistic point-source assumption. However, as earthquake magnitude increases, the influence of finite faults grows, demanding the adoption of finite faults in simulations for accurate ground motion estimates. We analyzed variations in simulated ground motions with and without the finite fault method for earthquakes with magnitude (Mw) ranging from 5.0 to 7.0, comparing pseudo-spectral acceleration. We also studied how slip distribution and hypocenter location affect simulations for a virtual earthquake that mimics the Gyeongju earthquake with Mw 5.4. Our findings reveal that finite fault effects become significant at magnitudes above Mw 5.8, particularly at high frequencies. Notably, near the hypocenter, the virtual earthquake’s ground motion significantly changes using a finite fault model, especially with heterogeneous slip distribution. Therefore, applying finite fault models is crucial for simulating ground motions of large earthquakes (Mw ≥ 5.8 magnitude). Moreover, for accurate simulations of actual earthquakes with complex rupture processes having strong localized slips, incorporating finite faults is essential even for more minor earthquakes.
Abstract
Recent earthquakes in Korea, like Gyeongju and Pohang, have highlighted the need for accurate seismic hazard assessment. The lack of substantial ground motion data necessitates stochastic simulation methods, traditionally used with a simplistic point-source assumption. However, as earthquake magnitude increases, the influence of finite faults grows, demanding the adoption of finite faults in simulations for accurate ground motion estimates. We analyzed variations in simulated ground motions with and without the finite fault method for earthquakes with magnitude (Mw) ranging from 5.0 to 7.0, comparing pseudo-spectral acceleration. We also studied how slip distribution and hypocenter location affect simulations for a virtual earthquake that mimics the Gyeongju earthquake with Mw 5.4. Our findings reveal that finite fault effects become significant at magnitudes above Mw 5.8, particularly at high frequencies. Notably, near the hypocenter, the virtual earthquake’s ground motion significantly changes using a finite fault model, especially with heterogeneous slip distribution. Therefore, applying finite fault models is crucial for simulating ground motions of large earthquakes (Mw ≥ 5.8 magnitude). Moreover, for accurate simulations of actual earthquakes with complex rupture processes having strong localized slips, incorporating finite faults is essential even for more minor earthquakes.
참고문헌 (15)
- Park DH, "Stochastic prediction of strong ground motion and attenuation equations in the southeastern Korean Peninsula", Journal of the Geological Society of Korea, 37(1), pp.21~30 (2001)
- Jo ND, "Stochastic prediction of strong ground motions in southern Korea", Journal of the Earthquake Engineering Society of Korea, 5(4), pp.17~26 (2001)
- Junn JG, "Stochastic prediction of strong ground motions in southern Korea", Geosciences Journal, 6(3), pp.203~214 (2002)
- Jo ND, "Estimation of spectrum decay parameter κ and stochastic prediction of strong ground motions in southeastern Korea", Journal of the Earthquake Engineering Society of Korea, 7(6), pp.59~70 (2003)
- Uchide T, "Fault rupture model of the 2016 Gyeongju, South Korea, earthquake and its implication for the underground fault system", Geophysical Research Letters, 45, pp.2257~2264 (2018)
- Song SG, "Static slip model of the 2017 Mw 5.4 Pohang, South Korea, earthquake constrained by the InSAR data", Seismological Research Letters, 90, pp.140~148 (2019)
- Cho E, "Rupture Process of the 2017Mw 5.5 Pohang, South Korea, Earthquake via an Empirical Green’s Function Method", Bulletin of the Seismological Society of America, 113(2), pp.592~603 (2023)[DOI]
- Hartzell SH, "Earthquake aftershocks as Green’s functions", Geophysical Research Letters, 5(1), pp.1~4 (1978)[DOI]
- Maechling PJ, "SCEC broadband platform : system architecture and software implementation", Seismological Research Letters, 86, pp.27~38 (2015)[DOI]
- Choi H, "Preliminary strong ground motion simulation at seismic stations within nuclear power plant sites in South Korea by a scenario earthquake on the causative fault of 2016 Gyeongju earthquake", Nuclear Engineering and Technology, 54(7), pp.2529~2539 (2022)[DOI]
- Boore DM, "Stochastic simulation of high-frequency ground motions based on seismological models of the radiated spectra", Bulletin of the Seismological Society of America, 73, pp.1865~1894 (1983)
- Beresnev IA, "FINSIM-a FORTRAN program for simulating stochastic acceleration time histories from finite faults", Seismological Research Letters, 69(1), pp.27~32 (1998)[DOI]
- Motazedian D, "Stochastic finite-fault modeling based on a dynamic corner frequency", Bulletin of the Seismological Society of America, 95(3), pp.995~1010 (2005)[DOI]
- Boore, DM, "Comparing stochastic point-source and finite-source ground-motion simulations: SMSIM and EXSIM", Bulletin of the Seismological Society of America, 99(6), pp.3202~3216 (2009)[DOI]
- Wells DL, "New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement", Bulletin of the Seismological Society of America, 84(4), pp.974~1002 (1994)