NERC-NSTC: Erosion in the deep ocean - the impact of the Kuroshio Current on the continental shelf and slope of Taiwan

NERC-NSTC：深海侵蚀——黑潮对台湾大陆架和斜坡的影响

• 批准号: NE/X003019/1
• 负责人: Uisdean Nicholson
• 金额: $ 10.32万
• 依托单位: Heriot-Watt University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX003019%2F1
• 关键词: NERC; NSTC; Erosion; deep; ocean

The global 'conveyor belt' of ocean currents are an important part of Earth's climate system, transporting heat and nutrients around the global oceans. They also transport large volumes of sediments and re-deposit these in large drifts in the deep oceans. These sediments then provide an important archive of the current systems that produced them, as well as changing temperatures and environmental conditions. In recent years, we have increasingly recognized that the large-scale eddies in the Earth's large surface currents, such as the Gulf Stream, also play an important role in the deep ocean. These eddies, which are equivalent to cyclones in the atmosphere, are concentrated at ocean fronts, and can cause deep erosion of the seabed - many hundreds of metres deep in some cases.The Kuroshio Current is one of these important surface current systems (associated with a front), that is a fundamental part of the ocean circulation system of the Pacific. Our recent work to the south of Taiwan, and offshore Japan, shows that this is a highly dynamic system which interacts with the complex seabed at an active margin (where two tectonic plates are colliding), deeply eroding and re-distributing sediment.In this project, we aim to understand the effect of the Kuroshio Current offshore Taiwan. We will use seismic reflection data, multibeam bathymetry data (proving high-resolution seabed maps) and core samples, to understand the impact of the current in a number of areas. We will specifically test how the current interacts with elevated tectonic ridges and whether it is capable of eroding deep channels across the continental shelf and slope. We will then investigate hazards associated with this deep erosion, including whether the removal of sediment from the plate boundary changes the stress state in the area, potentially with implications for earthquake magnitude and frequency - something that has never previously been tested - and whether the current destabilizes the continental slope, leading to underwater landslides and tsunamis. This project will also allow us to develop a new, long-term partnerships between our institutions in the UK, Germany and Taiwan, to expand this work in the future. The Kuroshio Current is relatively understudied but it is the ideal natural laboratory to understand the impact of ocean currents on continental margins, and address fundamental new questions about the links between the oceans and deep earth processes that have a major impact on human populations.

全球洋流“传送带”是地球气候系统的重要组成部分，在全球海洋周围输送热量和营养物质。它们还运输大量沉积物，并将这些沉积物以大漂流物的形式重新沉积在深海中。然后，这些沉积物提供了一个重要的档案，目前的系统，产生他们，以及不断变化的温度和环境条件。近年来，我们越来越认识到，墨西哥湾流等地球大型表层洋流中的大规模涡旋在深海也发挥着重要作用。这些涡流相当于大气中的气旋，集中在海洋锋面，可对海床造成深层侵蚀，有时可达数百米深。黑潮海流是这些重要的表层海流系统（与锋面有关）之一，是太平洋海洋环流系统的基本组成部分。我们最近在台湾南部和日本近海的工作表明，这是一个高度动态的系统，它与活动边缘（两个构造板块碰撞的地方）的复杂海底相互作用，深度侵蚀和重新分配沉积物。在本项目中，我们的目标是了解黑潮对台湾近海的影响。我们将利用地震反射数据、多波束测深数据（证明高分辨率海底地图）和岩心样本，了解海流对一些地区的影响。我们将具体测试海流如何与隆起的构造脊相互作用，以及海流是否能够侵蚀大陆架和陆坡上的深水道。然后，我们将调查与这种深层侵蚀相关的危害，包括从板块边界移除沉积物是否会改变该地区的应力状态，可能对地震震级和频率产生影响-以前从未测试过-以及电流是否会破坏大陆坡的稳定，导致水下滑坡和海啸。该项目还将使我们能够在英国，德国和台湾的机构之间建立新的长期合作伙伴关系，以扩大未来的工作。黑潮洋流相对而言研究不足，但它是了解洋流对大陆边缘影响的理想天然实验室，并解决有关海洋与对人类产生重大影响的地球深部过程之间联系的基本新问题。