Sandwaves on the Southeast Vietnam Shelf recorded by high resolution seismic profiles: formation and mechanism
Sandwaves on the Southeast Vietnam Shelf recorded by high resolution seismic profiles: formation and mechanism
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高分辨率地震剖面记录的越南东南陆架沙波：形成与机制
DOI：
10.1007/s11707-009-0002-z
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
T. Phi
中科院分区：
文献类型：
--
作者：
V. Bui;A. Schimanski;K. Stattegger;P. Phung;T. H. Nguyen;Trung;T. Phi
利用声波震源的高分辨率地震资料，揭示了越南东南部大陆架大尺度地貌（沙波）的广泛分布。波浪高几米、波长长数百米的河床主要发育在内陆架（20-40米），被认为是在当今海洋水动力条件下形成的。这些在大陆最北端较深水域（120 m）发育的河床可以解释为晚更新世海平面最末低潮时期形成的遗存形态特征。根据背风方向确定了两条沉积物输运路径：东北-西南（沿岸）和南北（跨岸）。根据沙波尺寸、地表沉积物和测量数据，构建了定量的海底潮流图。最强的洋流速度在向西南方向逐渐减弱，由北部的大沙波表示（场B）。水深、表层沉积物组成和底流是控制河床发育的三个因素。
The application of high resolution seismic data using boomer sound source has revealed a wide distribution of large-scale bedforms (sandwaves) on the Southeast Vietnam continental shelf. Bedforms that are a few meters high in wave height and hundreds of meters long in wavelength are primarily developed in the inner shelf (20–40 m) and considered to be formed under the present-day marine hydrodynamic conditions. Those bedforms developed in the deeper water (120 m) of the northernmost part of the continent can be interpreted as the relict morphological features formed during the latest sea-level lowstand of the late Pleistocene period. Two sediment transport paths have been identified on the basis of the bedform’s leeward orientation: northeast-southwest (along-shore) and north-south (cross-shore). A quantitative bottom current map is constructed from sandwave dimensions, surface sediments and measurement data. The strongest current velocities that gradually decrease toward the southwest are indicated by large sandwaves in the north (field B). Water depth, surficial sediment composition and bottom current are three factors that control the development of bedforms.