Laboratory study: Sediment transport in wave-supported gravity currents

霍纳-德维纳摘要PI将结合一系列实验室实验和现场观测，目的是提高我们对波浪支持的重力流(WSGC)垂直结构的理解。具体地说，拟议的实验室研究将探讨是否仅通过再悬浮就能达到启动下坡输送所需的高浓度悬浮泥沙，或者是否需要泥沙汇聚。这项工作对广泛环境中的泥沙运移具有重要意义。以前在高能海洋环境中观察到的高浓度流体泥浆在很大程度上仅限于河流沉积物输入极高的地区。了解沉积物供给对这种沉积物输运方式的形成和启动的作用，将有助于加深对跨陆架沉积物输运的认识。波浪支持的浑浊流的跨陆架输送是一种新发现的、潜在的主导机制，可以将细颗粒沉积物(以及相关成分，如碳和污染物)移动到大陆架上。该项目还将支持一名研究生，加强本科课程，并通过华盛顿大学开放之家向大学预科学生提供外展服务。

Horner-DevineAbstractThe PIs will combine a series of laboratory experiments with field observations with the aim of improving our understanding of the vertical structure of wave supported gravity currents (WSGC). Specifically, the proposed laboratory studies will address whether the high concentrations of suspended sediment necessary to initiate down-slope transport can be achieved solely by resuspension, or whether sediment convergence is necessary. The work has important implications for sediment transport in a wide range of environments. Previous observations of high concentration fluid muds in energetic oceanic environments have been largely limited to areas with extremely high fluvial sediment input. Understanding the role of sediment supply to the formation and initiation of this mode of sediment transport will improve the understanding of cross-shelf sediment transport. Across-shelf transport by wave-supported turbidity currents is a newly identified, potentially dominant mechanism for moving fine sediment (and associated constituents such as carbon and contaminants) across continental shelves. The project will also support one graduate student, enhance undergraduate courses, and provide outreach to pre-college students through the UW Open House.