Stability of submarine slopes in the northern South China Sea: a numerical approach

doi:10.1007/s00343-013-2060-z

IOCAS-IR > 海洋地质与环境重点实验室

	Stability of submarine slopes in the northern South China Sea: a numerical approach
	Zhang Liang1,2 ; Luan Xiwu 3,4; Luan, XW
	2013
发表期刊	CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY
ISSN	0254-4059
卷号	31 期号:1 页码:146-158
文章类型	Article
摘要	Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained (I broken vertical bar=0) cases. Results show that submarine slopes are stable when the slope is < 16A degrees under static conditions and without a weak interlayer. With a weak interlayer, slopes are stable at < 18A degrees in the drained case and at < 9A degrees in the undrained case. Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure. The slope became unstable at > 13A degrees with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes > 10A degrees, and > 3A degrees for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.; Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained (I broken vertical bar=0) cases. Results show that submarine slopes are stable when the slope is < 16A degrees under static conditions and without a weak interlayer. With a weak interlayer, slopes are stable at < 18A degrees in the drained case and at < 9A degrees in the undrained case. Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure. The slope became unstable at > 13A degrees with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes > 10A degrees, and > 3A degrees for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.
关键词	Submarine Landslide Factor Of Safety Earthquake South China Sea
学科领域	Marine & Freshwater Biology ; Oceanography
DOI	10.1007/s00343-013-2060-z
URL	查看原文
收录类别	SCI
语种	英语
WOS研究方向	Marine & Freshwater Biology ; Oceanography
WOS类目	Limnology ; Oceanography
WOS记录号	WOS:000313654000017
WOS关键词	CONTINENTAL-SLOPE ; STOREGGA SLIDE ; MUD VOLCANOS ; SEDIMENTS ; MARGINS ; AREA ; INSTABILITY ; LANDSLIDES ; MECHANISMS ; FAILURES
WOS标题词	Science & Technology ; Life Sciences & Biomedicine ; Physical Sciences
引用统计	被引频次：10[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/16318
专题	海洋地质与环境重点实验室
通讯作者	Luan, XW
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China 3.Minist Land & Resources, Key Lab Marine Hydrocarbon Resources & Environm G, Qingdao 266071, Peoples R China 4.Qingdao Inst Marine Geol, Qingdao 266071, Peoples R China
第一作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	Zhang Liang,Luan Xiwu,Luan, XW. Stability of submarine slopes in the northern South China Sea: a numerical approach[J]. CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY,2013,31(1):146-158.
APA	Zhang Liang,Luan Xiwu,&Luan, XW.(2013).Stability of submarine slopes in the northern South China Sea: a numerical approach.CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY,31(1),146-158.
MLA	Zhang Liang,et al."Stability of submarine slopes in the northern South China Sea: a numerical approach".CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY 31.1(2013):146-158.

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