| Author's Name: XU Xiaoyong, Lü Fuliang, WANG Dawei, WANG Bin,
SUN Hui, SHAO Dali, LU Yintao, MA Hongxia |
| Institution: PetroChina Hangzhou Research Institute of Geology, |
| Abstract: |
| Cyclic steps refer to the bedforms of long-wave(the ratio of wavelength to wave height ?垌1), migrating upstream and being upper-flow-regime in turbidity current. They are bounded by internal hydraulic jump and commonly occur at steep slopes and slope breaks. This paper reviews the research status of cyclic steps and other related supercritical bedforms. Three examples from continental margins in United States, Canada, and South China Sea are presented based on high-resolution multi-beam sonar data and seismic data. This paper also present the results of monitoring and numerical modeling of turbidity currents in the Squamish prodelta, British Columbia, Canada. The controlling factors and the distribution of cyclic steps were discussed based on numerical modeling. The cyclic steps in active submarine canyon-channel system are relatively small (tens of meters in wavelength and few meters at height), while the cyclic steps in the unconfined levee system and the channel-lobe transition zone are relatively larger (above one kilometer in wavelength and hundreds of meters at height). Cyclic steps and related supercritical turbidity bedforms may have important influence for the deep water sediments in slope area, which can help to better understand the evolution of deep water channel-levee system, and to predict the oil and gas reservoirs of deep water. |
| Keywords: cyclic steps; supercritical current; bedforms; deep water sediments |
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投稿时间：
2017-11-12 |
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