Collaborative Research: The effect of sand fraction and event evolution on fine-sediment transport and the depositional record in wave-supported mud flows

合作研究：砂粒分数和事件演化对细粒沉积物运移和波浪支撑泥浆流沉积记录的影响

• 批准号: 1537231
• 负责人: Tian-Jian (Tom) Hsu
• 金额: $ 25.96万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1537231&HistoricalAwards=false
• 关键词: Collaborative; Research; effect; sand; fraction

Part 1Offshore delivery of fine sediment on the continental shelf via wave supported gravity currents (WSGC) is a key component of sediment transport fromsource to sink, yet it remains poorly understood. Current models of this process focus on suspension and transport of silt and clay sized particles. However, recent laboratory experiments show that even a small amount of sand in the sediment layer may exert a dominant control on the dynamics of the transport layer. The proposed effort will investigate the effect of sand fraction on sediment transport in WSGC, particularly, the transition between transport modes, the downslope transport and the depositional signatures. The objectives will be addressed using a comprehensive series of laboratory experiments, 3D turbulence-resolving numerical simulations, and re-analysis of existing field data from WSGC on active continental margins. The work is relevant to a broad range of fields, from fluid mechanics and water resource engineering, to studies of biogeochemical cycles. Outreach include introduction of the relevance of sedimentary processes to K-12 students with hand-on experiments in the university labs, and invited presentations to local schools. Undergraduate and graduate students will be involved. In addition to journal papers and conference presentations, open-source codes will be disseminated through Community Surface Dynamics Modeling System (CSDMS) framework.Part 2Offshore delivery of fine sediment on the continental shelf via wave supported gravity currents (WSGC) is a key component of sediment source to sink, yet it remains poorly understood. Current models of this process focus on suspension and transport of silt and clay sized particles. However, recent laboratory experiments show that even a small amount of sand in the sediment layer may exert a dominant control on the dynamics of the transport layer. The proposed effort investigates the effect of sand fraction on sediment transport in WSGC, particularly, the transition between transport modes, the downslope transport and the depositional signatures. The project is formed around two main objectives: 1) Determine the role of the sand fraction in controlling dynamics and transport within WSGC and the bed deposits associated with them. 2) Evaluate impacts of event evolution (surging and waning of a storm) on the sediment and flow dynamics within a gravity flow and the resulting depositional signatures These will be addressed using a comprehensive series of laboratory experiments, 3D turbulence-resolving numerical simulations, and re-analysis of existing field data from WSGC on active continental margins. The work is relevant to a broad range of fields, from fluid mechanics and water resource engineering, to studies of biogeochemical cycles. Outreach include introduction of the relevance of sedimentary processes to K-12 students with hand-on experiments in the university labs, and invited presentations to local schools. Undergraduate and graduate students will be involved. In addition to journal papers and conference presentations, open-source codes will be disseminated through Community Surface Dynamics Modeling System (CSDMS) framework.

第1部分通过支持的重力电流（WSGC）在大陆架上的精细沉积物的交付是从供水到下沉的沉积物传输的关键组成部分，但它仍然鲜为人知。该过程的当前模型集中于淤泥和粘土大小颗粒的悬浮和运输。但是，最近的实验室实验表明，即使是沉积物层中的少量沙子也可能对传输层动力学产生主要控制。拟议的努力将调查沙子分数对WSGC沉积物传输的影响，特别是运输模式，下坡运输和沉积特征之间的过渡。这些目标将使用一系列全面的实验室实验，3D湍流分辨的数值模拟以及对活性大陆边缘的WSGC现有现场数据进行重新分析。这项工作与从流体力学和水资源工程到生物地球化学周期的研究相关的广泛领域。外展包括在大学实验室中对K-12学生进行沉积过程的相关性，并邀请向当地学校演讲。 本科生和研究生将参与其中。除期刊论文和会议演示外，开源代码还将通过社区表面动态建模系统（CSDMS）框架传播。第2部分通过波浪支撑的重力电流（WSGC）在大陆架上的良好沉积物在大陆架上交付（WSGC）是沉积物的关键成分，但仍然很少了解。该过程的当前模型集中于淤泥和粘土大小颗粒的悬浮和运输。但是，最近的实验室实验表明，即使是沉积物层中的少量沙子也可能对传输层动力学产生主要控制。拟议的努力研究了沙子级分对WSGC沉积物传输的影响，特别是运输模式，下坡运输和沉积特征之间的过渡。该项目围绕两个主要目标形成：1）确定沙子分数在控制WSGC内部动力和运输方面的作用以及与之相关的床位。 2）评估事件演化的影响（暴风雨的飙升和减弱）对重力流中的沉积物和流动动力学的影响以及由此产生的沉积签名将使用全面的实验室实验，3D湍流分辨率的数值模拟，以及从WSGC上的现有现场数据重新分析现有的现有现场数据。这项工作与从流体力学和水资源工程到生物地球化学周期的研究相关的广泛领域。外展包括在大学实验室中对K-12学生进行沉积过程的相关性，并邀请向当地学校演讲。 本科生和研究生将参与其中。除期刊论文和会议演讲外，开源代码还将通过社区表面动态建模系统（CSDMS）框架传播。