In Situ Variability of Large Aggregates over a Fluid Mud Bed: Shear Effects, Settling Velocities and Response to Storms

流化泥床上大骨料的原位变化：剪切效应、沉降速度和对风暴的响应

• 批准号: 9000134
• 负责人: John Wells
• 金额: $ 10.09万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 1993-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9000134&HistoricalAwards=false
• 关键词: Situ; Variability; Large; Aggregates; over

Previous work by the Dr. Wells has demonstrated that organically bound aggregates of mineral grains are relatively common to estuarine water along the N. Carolina coast. These aggregates (500 microns) are a food source for marine organisms, affect chemical distributions, and may be responsible for a substantial part of the vertical mass flux in shallow water. Few workers have been able to either observe or recover this "marine snow". Using techniques developed in their previous NSF award, Dr. Wells and his collaborator Dr. Luettich will analyze the in situ characteristics of these aggrregates. Transects of stations across Cape Lookout Bight will be re-occupied every 3 months for 2 years, vertical profiles will be re-occuppied every 3 months for 1 year, and moorings will be left in place for the duration of 3 "northeaster" storms. Photographs of aggregates, in situ measurements of aggregate settling velocities, and sensors recording a variety of water column propoerties on moorings and tethered cables will: 1) yield details about the size, shape and abundance of large aggregates in Cape Lookout Bight and Barden Inlet; 2) investigate the effect of currents on large aggregates; 3) provide settling velocities of aggregates; and 4) provide insight into the reponse of large aggregates to storm events and other seasonal phenomena.

威尔斯博士先前的工作已经证明， 矿物颗粒的有机结合集合体相对 常见于沿着北的河口水。卡罗莱纳海岸。这些 聚集体（500微米）是海洋生物的食物来源， 影响化学分布，并可能导致 浅水区垂直质量通量的很大一部分。几 工作人员已经能够观察到或恢复这个“海洋”， 雪”。利用他们在以前的NSF奖项中开发的技术， 威尔斯博士和他的合作者Luettich博士将分析 这些集合体的原位特征。断面 整个Cape Lookout Bight的车站将每3个月重新占用一次 2年内，垂直剖面将每隔 3个月为1年，系泊将留在原地， 三场“东北风”风暴。集料照片，以 骨料沉降速度的现场测量，以及 传感器记录了各种水柱的特性， 系泊和系留电缆将：1）产生有关 Cape Lookout大型聚集体的大小、形状和丰度 Bight和Barden Inlet; 2）研究海流对 大骨料; 3）提供骨料的沉降速度; 和4）提供洞察大骨料的反应， 风暴事件和其他季节性现象。