Thorium-234 based estimation of residence time of bottom-near particulate matter in the Mecklenburger Bucht .

基于钍 234 的梅克伦堡湾近底部颗粒物停留时间估计。

• 批准号: 233255247
• 负责人: Professor Dr. Gerhard Graf
• 金额: --
• 依托单位: Lehrstuhl für Meeresbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/233255247?language=en
• 关键词: Thorium; 234; based; estimation; residence

Particle fluxes between water and sediments represent a significant fraction of the matter cycling between the pelagic and benthic system. Thus a permanent exchange between the benthic turbidity zone (BTZ) and the bioturbated sediment layers is provided, which in the case of the deep-sea occurs in the time scale of a few days (resuspension loop).This proposal aims to determine residence time of particles in the water, the BTZ and the sediment of the south-western Mecklenburger Bucht using the 234 Thorium/238Uranium equilibrium. In order to apply this approach, which was proven for the deep-sea, in a shallow water situation, some specific constraints have to be considered, especially the adsorption of Thorium on particles with higher mineral content and with relatively fresh organic compounds (Alginin, Fucoidan und Chondroitin; Co-operation with Prof. Carol Arnosti, Chapal Hill, USA). In addition flume experiments should be carried out in order to test the effect of increased turbulences and bottom shere on the thorium adsorption. The second year is dedicated to a field study to measure residence time and POC on a transect from shallow sandy to deeper silty sediment. Thus the residence time of POC in different types of sediments and the other compartments of the resuspension loop can be calculated.

水和沉积物之间的粒子通量代表了中上层和底栖系统之间物质循环的很大一部分。因此，提供了底栖浊度带 (BTZ) 和生物扰动沉积层之间的永久交换，在深海的情况下，这种交换在几天的时间尺度内发生（再悬浮循环）。该提案旨在使用 234 钍/238 铀平衡确定水、BTZ 和梅克伦堡布赫特西南部沉积物中颗粒的停留时间。为了应用这种已在深海、浅水情况下得到验证的方法，必须考虑一些特定的限制，特别是钍在矿物质含量较高和相对新鲜的有机化合物颗粒上的吸附（海藻酸、褐藻糖胶和软骨素；与美国 Chapal Hill 的 Carol Arnosti 教授合作）。此外，应进行水槽实验，以测试增加的湍流和底部剪切力对钍吸附的影响。第二年致力于实地研究，测量从浅层沙质到较深粉质沉积物的横断面上的停留时间和 POC。因此，可以计算 POC 在不同类型沉积物和再悬浮回路的其他区室中的停留时间。