A missing link between continental shelves and the deep sea: Have we underestimated the importance of land-detached canyons?

大陆架和深海之间缺失的联系：我们是否低估了与陆地分离的峡谷的重要性？

基本信息

批准号：
2892792
负责人：
金额：
--
依托单位：
University of Southampton
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2892792
关键词：
missing link between continental shelves

项目摘要

Submarine canyons are assumed to be globally-significant conduits for the transfer of sediment, nutrients, organic carbon and pollutants between continental shelves and the deep sea. However, efforts to directly quantify contemporary particulate fluxes through submarine canyons have focused solely on a handful of canyons that directly connect to rivers or coastal littoral cells1. Because of the long-standing paradigm that canyons whose heads lie 100s of km from shore are quiescent in terms of sediment transport, these 'land-detached' canyons have often been overlooked by hydrodynamic monitoring; despite accounting for more than three quarters of the >9000 submarine canyons worldwide2. Without measurements, we cannot quantify particulate fluxes in land-detached canyons, exposing a major gap in understanding of global sediment routing systems and shelf to deep-sea exchanges. New measurements in the Whittard Canyon, Celtic Margin2 (>250 km from shore) recorded powerful turbidity currents, of a surprisingly similar frequency and magnitude to those reported in major land-attached canyons3. These new results challenge the long-held paradigm, but questions remain concerning what triggers these flows, the volumes of material they transport, and the efficiency by which they bury natural sediments and anthropogenic pollutants. This project will tackle these important questions, using new data from Whittard Canyon.

假定海底峡谷是在大陆架子和深海之间转移沉积物，养分，有机碳和污染物的全球意义上的管道。但是，通过海底峡谷直接量化当代颗粒通量的努力仅关注直接连接到河流或沿海沿海细胞的少数峡谷。由于距离岸边100 km的峡谷长期存在的范式在沉积物运输方面是静止的，因此这些“陆上荒地”的峡谷经常被水动力监测所忽略。尽管在全球范围内占了> 9000次海底峡谷中的四分之三以上。如果没有测量，我们将无法量化陆地上峡谷中的颗粒物通量，从而在理解全球沉积物路由系统和架子上的主要差距到深海交换。 Whittard Canyon，Celtic Margin2（距离岸边> 250公里）的新测量值记录了强大的浑浊电流，与在主要土地连接的峡谷中报道的频率和幅度非常相似。这些新结果挑战了长期范式的范式，但是关于触发这些流动，它们运输的材料的数量以及它们掩埋天然沉积物和人为污染物的效率的问题仍然存在。该项目将使用Whittard Canyon的新数据来解决这些重要问题。