NSFGEO-NERC: Collaborative Research: Coupling Erosion, Weathering, and Hydrologic Function in an Active Orogenic System

NSFGEO-NERC：合作研究：活跃造山系统中侵蚀、风化和水文功能的耦合

• 批准号: NE/V012037/1
• 负责人: Edward Tipper
• 金额: $ 31.13万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV012037%2F1
• 关键词: NSFGEO; NERC; Collaborative; Research; Coupling

The collision of continents driven by the movement of the Earth's tectonic plates raises the Earth's greatest mountain ranges. This has fundamental impacts on the habitability of large areas of the continents as well as controlling their geological evolution and moderating global climate. The prime modern example of a continental collision is the northward movement of India colliding with Asia which has raised the Himalayas and Tibet over the last 50 million years. This region sources freshwater for more than one-fifth of the global population and the floodplains of the rivers draining the region provide their food. The Himalayas and Tibet have a major impact on the climate of east and south-east Asia dominated by the summer monsoonal rains. The mountain range is the source of the major natural hazards in the region including earthquakes, landslides and floods. Continental collisions also have a major impact on the geological evolution the continental crust deforming, burying, heating and melting the crust and the associated uplift and erosion provides large amounts of sediment. The continental collisions are also thought to play an important part in moderating global climate on the greater than million-year timescales as the chemical reactions between carbon-dioxide dissolved in rainwater and the eroded sediment enhance the flux of dissolved carbon-dioxide and calcium to the oceans to be deposited as limestone removing carbon-dioxide from the atmosphere and limiting global temperatures.However the evolution of collisional mountain ranges involves complex interactions between tectonics, erosion and climate. The collision thickens the continents which elevates their surface topography, enhances erosion by landslides and the steeper river profiles. The topographic elevation also alters the local climate, for example by increasing rainfall which enhances erosion by increasing landslide frequency and the ability of rivers to transport sediments. The evolving topography of mountain belts is thought to represent a balance between the thickening of the continental crust by the collision balanced by the tendency of the thickened crust to spread under its own weight and the erosion of the crust forced by the topography and local climatic impacts. This project will study these complex interactions between the tectonic processes, the erosive processes dominated by landslides and the impact of climate by studying the Melamchi Khola river catchment in Nepal. The catchment spans the dramatic gradient in topography from the foothills to the high mountains, a gradient which is reflected by a marked increase in erosion rates towards the high mountains. The detailed study in one location will enable us to understand the interactions between the controlling processes. For example how does the exhumation rate control landslide formation and the erosion rate. How does the local climate, particularly rainfall, impact this relationship? How does removal of rock by erosion impact the controlling tectonics and propensity for earthquakes and landslides? The work will involve: 1) Determining how the physical and chemical properties of rock change by fracturing and chemical alteration as groundwater flows through the fractures as they are brought to the surface and the relationship of these changes to both the local tectonics and to climate. 2) Quantify how the topography is shaped by the competing processes of tectonically-driven uplift and erosion by landslides. How are these major processes impacted by the evolution of the rock mass and the groundwater flow through the subsurface. 3) Determine the flow paths of water as rain falls on the mountains and then enters fractured rock before feeding rivers below. 4) Quantify how the chemical alteration of the rock depends on the local climate (temperature and rainfall), groundwater flow paths and erosion rate.

地球构造板的运动驱动的大陆碰撞使地球上最伟大的山区范围升高。这对大陆大区域的可居住性以及控制其地质进化和调节全球气候具有根本的影响。大陆碰撞的主要现代例子是印度的北部运动与亚洲相撞，在过去的5000万年中，亚洲兴起了喜马拉雅山脉和西藏。该地区为淡水提供了超过五分之一的全球人口，而排水河流的洪泛区则提供了他们的食物。喜马拉雅山脉和西藏对以夏季季风降雨为主的东亚和东南亚气候产生了重大影响。山脉是该地区主要自然危害的根源，包括地震，滑坡和洪水。大陆碰撞还对地质进化产生了重大影响。大陆地壳变形，埋入，加热和融化地壳以及相关的隆起和侵蚀提供了大量的沉积物。陆期碰撞还被认为在调节全球气候上的重要角色中起着重要作用范围涉及构造，侵蚀和气候之间的复杂相互作用。碰撞使大陆增厚，从而提高了其表面形态，增强了滑坡和较陡的河流剖面的侵蚀。地形海拔高度也改变了当地的气候，例如，增加降雨量，从而通过增加滑坡频率和河流运输沉积物的能力来增强侵蚀。人们认为，不断发展的山带的地形被认为是在大陆地壳增厚之间通过碰撞平衡的平衡，这是由于外壳在其自身的重量下散布的趋势，以及由地形和局部气候影响强迫的地壳的侵蚀。该项目将通过研究尼泊尔的Melamchi Khola河流集水区，研究以滑坡为主的构造过程，侵蚀过程和气候影响之间的这些复杂相互作用。流域跨越了从山麓到高山的地形中戏剧性的梯度，这种梯度反映出，侵蚀率显着增加，向高山。一个位置的详细研究将使我们能够了解控制过程之间的相互作用。例如，挖掘率如何控制滑坡的形成和侵蚀率。当地气候，尤其是降雨如何影响这种关系？通过侵蚀将岩石拆除如何影响控制地震和滑坡的控制构造和倾向？工作将涉及：1）确定岩石的物理和化学特性如何通过压裂和化学改变时如何随着地下水流过裂缝而变化，以及这些变化与局部构造和气候之间的关系。 2）量化地形是如何通过横向驱动的隆起和滑坡侵蚀的竞争过程来塑造的。这些主要过程如何受岩体质量的演变和地下水流的进化影响。 3）当雨水落在山上，然后在下面进食河流之前，确定水的流动路径。 4）量化岩石的化学改变如何取决于局部气候（温度和降雨），地下水流道和侵蚀速率。

项目成果

The efficacy of enhancing carbonate weathering for carbon dioxide sequestration

• DOI: 10.3389/fclim.2022.928215
• 发表时间: 2022-08-11
• 期刊: FRONTIERS IN CLIMATE
• 作者: Knapp, William J.;Tipper, Edward T.
• 通讯作者: Tipper, Edward T.