Morphology of submarine barchans and sediment transport in barchans fields off the Dongfang coast in Beibu Gulf

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Morphology of submarine barchans and sediment transport in barchans fields off the Dongfang coast in Beibu Gulf
	Ma, Xiaochuan; Yan, Jun; Fan, Fengxin
刊名	GEOMORPHOLOGY
	2014-05-15
卷号	213 页码:213-224
关键词	Submarine barchan Morphology Mobility Sediment transport Beibu Gulf
通讯作者	Ma, XC (reprint author), Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China.
英文摘要	Submarine barchans in three new regions were described using new high-resolution multibeam bathymetric data off the Dongfang coast in Beibu Gulf. Currents, seismic profiles of horns, surface sediments and comparative surveys in 2007 and 2009 were obtained to study barchan mobility and sand transport in the barchan fields. The submarine barchans occur at depths of 15-25 m, reaching up to 551.9 m in horn length and 8.6 m in height Most barchans have asymmetrical horns and display wider plane shapes than subaerial barchans for the same length and height. The morphology of barchans exhibits regional variations that are mainly controlled by finite water depth, daily reverse currents, sand supply changes and interaction of dunes. Barchan asymmetries, internal bedding inclinations and grain size changes are in agreement with the dominant current directions. Results show that submarine barchans migrated 5-43 m in two years (2007-2009) through comparison of bathymetric data. Because of the marginally cohesive fine sediment composition and long distance from contemporary sediment sources, it is believed that barchans in region C are not of modern origin. However, these bedforms can be also affected by high energy flow regimes. Collisions limit barchan widths and provide efficient transport paths between barchans on their horns. Large sand supply through the horns increases the barchan heights and also changes their shapes. Some small dunes are identified that are moving away from the barchans field in 2007 and have departed from the host barchans in 2009. These small barchans were probably caused by the separation of the faster-moving horn tails from the host barchans when extreme situations happen. The mechanism gives a new explanation for sand loss and size determination of submarine barchans. (C) 2014 Elsevier B.V. All rights reserved.
学科主题	Physical Geography; Geology
收录类别	SCI
语种	英语
WOS记录号	WOS:000335111800017
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/23828]
专题	海洋研究所_海洋地质与环境重点实验室
作者单位	Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China
推荐引用方式 GB/T 7714	Ma, Xiaochuan,Yan, Jun,Fan, Fengxin. Morphology of submarine barchans and sediment transport in barchans fields off the Dongfang coast in Beibu Gulf[J]. GEOMORPHOLOGY,2014,213:213-224.
APA	Ma, Xiaochuan,Yan, Jun,&Fan, Fengxin.(2014).Morphology of submarine barchans and sediment transport in barchans fields off the Dongfang coast in Beibu Gulf.GEOMORPHOLOGY,213,213-224.
MLA	Ma, Xiaochuan,et al."Morphology of submarine barchans and sediment transport in barchans fields off the Dongfang coast in Beibu Gulf".GEOMORPHOLOGY 213(2014):213-224.