Tide-driven sediment variations on a large compound dune in the Jade tidal inlet channel, South-Eastern North Sea
Tide-driven sediment variations on a large compound dune in the Jade tidal inlet channel, South-Eastern North Sea
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北海东南部玉石入潮水道大型复合沙丘的潮汐驱动沉积物变化
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
D. Hebbeln
中科院分区：
文献类型：
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作者：
C. Svenson;V. Ernstsen;C. Winter;A. Bartholomä;D. Hebbeln
SVENSON， C， ERNSTSEN, v.b.， WINTER， C.和HEBBELN， D. 2009。北海东南部玉潮入口通道大型复合沙丘的潮汐驱动沉积物变化。沿海研究学报，SI 56（第十届国际沿海研讨会论文集），361 - 365。为了解水下沙丘的局部水动力、沉积参数和几何形状之间的相互作用，研究了北海东南部Jade潮汐入口通道（German Bight, German Bight）一个大型退潮导向复合沙丘（L180m, H5m）的粒度格局的空间多样性和时间变化。在潮汐移相过程中，重复测量了高分辨率测深剖面和流速剖面，并采集了72个表层沉积物样品。泥沙参数已导出来描述粒度组成和统计，在空间和时间。平均粒径为460 μm的中砂为优势组分，覆盖了沙丘的大部分背风侧和背风侧。而沙丘两侧的平均粒径则从下风面和背风面350 μm的中沙增加到峰顶700 μm的粗沙。在分选方面，床质向顶部分选效果较好。在波峰区，细组分的比例在淡水期下降，在背风区，细组分和粗组分的比例在加速涨潮和退潮期都增加。从波谷到波峰的显著粗化趋势可以解释为流向波峰区的流速和输送能力的增加。到目前为止，对时间趋势的解释还不可行。附加指标词：地形，粒度，沉积物趋势
SVENSON, C., ERNSTSEN, V.B., WINTER, C. and HEBBELN, D. 2009. Tide-driven sediment variations on a large compound dune in the Jade tidal inlet channel, Southeastern North Sea. Journal of Coastal Research, SI 56 (Proceedings of the 10th International Coastal Symposium), 361 – 365. Lisbon, Portugal, ISSN 0749-0258 To understand the interplay of the local hydrodynamics, sediment parameters and geometry of subaqueous dunes, the spatial diversity and temporal change of grain size patterns of a large ebb directed compound dune (L 180m, H 5m) in the Jade tidal inlet channel (German Bight, Southeastern North Sea) were studied. In the course of shifting tidal phases, repeated high resolution bathymetry and current velocity profiles were measured and 72 surface sediment samples were collected. Sediment parameters have been derived to describe grain size composition and statistics, in both space and time. Medium sand with an average mean grain size of 460 μm was the predominant fraction, covering most of the stoss and lee side of the dune. However, across the dune the mean grain size increased from medium sand of 350 μm at the lower lee and stoss sides to coarse sand of 700 μm on the crest. Regarding grain sorting, the bed material was better sorted towards the crest. Temporal sediment patterns were observed in the crest region, where the proportion of fine components decreased in the slack water phases and in the lee zone, where both fine and coarse components increased in proportion during the accelerated flood and ebb phases. The significant coarsening trend from trough to crest can be explained by an increase in flow velocity and transport capacity towards the crest region. So far interpretations of temporal trends are not feasible. ADITIONAL INDEX WORDS: bedforms, grain size, sediment trend