日本地球惑星科学連合2024年大会

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[J] ポスター発表

セッション記号 S (固体地球科学) » S-GD 測地学

[S-GD02] 地殻変動

2024年5月31日(金) 17:15 〜 18:45 ポスター会場 (幕張メッセ国際展示場 6ホール)

コンビーナ:富田 史章(東北大学災害科学国際研究所)、加納 将行(東北大学理学研究科)、野田 朱美(気象庁気象研究所)、姫松 裕志(国土地理院)

17:15 〜 18:45

[SGD02-P08] Seismic potential of Main Recent Fault in Iran: Interseismic fault locking, slip rate and earthquake recurrence interval

*Jyr-Ching Hu1、Ying-Hui Yang2、Ali Yassaghi3 (1.Department of Geosciences, National Taiwan Univ.、2.State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu Univ. of Technology, Chengdu, Sichuan, China、3.Department of Geology, Tarbiat Modares Univ., Tehran, Iran)

キーワード:Seismic potential , InSAR, Main Recent Fault, Fault locking

The Main Recent Fault (MRF) is an important geological boundary fault that accommodates the oblique convergence motion between the Arabian and Eurasian plates. Several large earthquakes including the 1909 Mb 7.4, the 1958-1963 sequence of three events with magnitude larger than Mw 6.0, and the 2006 Mw 6.1 earthquake had partly ruptured the central and southeast segments of MRF. However, no large earthquake occurred in the northwest segment in the past hundred years. In this study, the interseismic surface deformation is firstly mapped from the Synthetic Aperture Radar (SAR) images acquired by the Sentinel-1 satellite. Then, the fault slip rate, coupling ratio and locking depth are estimated along the fault based on the measured interseismic surface deformation. The results show that the interseismic fault motion is controlled by a dominant dextral strike-slip with slightly varies from ~4.0 mm/yr to ~6.3 mm/yr along the MRF. Furthermore, it is also found a non-negligible extensional motion with average rate of ~4.7 mm/yr in the northwest segment of MRF. In addition, seven sub-segments could be divided based on the fault coupling distribution and historical earthquakes in the area of interest. According to the potential seismic magnitude and estimated recurrence interval, it is found that several sub-segments are approaching the end of their interseismic recurrence interval. Meanwhile, one sub-segment (SF-6) may be in the early stage of a new recurrence period due to the recent several large earthquakes and a long recurrence interval.