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추계학적 지진동 모사에서 유한단층 모델의 민감도 분석

Sensitivity Analysis of Finite Fault Model in Stochastic Ground Motion Simulations

  • 이상현 (서울대학교 지구환경과학부) ;
  • 이준기 (서울대학교 지구환경과학부)
  • Lee, Sang-Hyun (School of Earth and Environmental Science, Seoul National University) ;
  • Rhie, Junkee (School of Earth and Environmental Science, Seoul National University)
  • 투고 : 2023.12.14
  • 심사 : 2024.03.26
  • 발행 : 2024.05.01

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.

키워드

과제정보

본 논문은 원자력안전위원회의 재원으로 한국원자력안전재단의 지원을 받아 수행한 원자력안전연구사업의 연구(RS-2023-00239569)의 일환으로 수행되었음.

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