Coupling between crustal superstructure, infrastructure and surface processes: test along the Himalayan orogenic front

地球的地圈、大气层、水圈和生物圈在各种空间和时间尺度上以不同的方式相互作用。研究气候和侵蚀对构造的影响(研究地壳和影响地壳的力量)是地质科学中最活跃的研究课题之一。喜马拉雅山脉是大陆碰撞形成的原型山脉，其南部堡垒是测试地球内部和表面过程相互作用的特殊天然实验室。例如，印度夏季风对喜马拉雅山脉的侵蚀起着至关重要的作用，自大约1200万年前建立以来，其强度变化很大。相反，自约5500万年前印度与欧亚大陆开始碰撞以来，喜马拉雅构造板块的运动一直相当稳定。由于在整个2000公里宽的山脉中发现了相同类型的岩石，所观察到的地表地质变化很可能是由于侵蚀在空间和时间上的变化。喜马拉雅山脉的形成目前由两种截然不同的构造模型来解释，这两种模型对沿主要构造的变形序列的预测不同。这项调查的基本原理是提供主要地质构造的年龄和侵蚀速率的综合研究，作为对模型预测的实地检验。这将提供有关中地壳和上地壳之间形变耦合的重要信息，并最终提供关于地壳深层形变与地表过程之间的联系的重要信息。洪水、山体滑坡、泥石流甚至地震都是在构造活跃地区形成动态景观的过程的后果。了解地球表面这种物质传输系统的速度和可变性，以及了解地球在地质时期对气候变化的反应，将有助于更好地预测灾害。除了在该学科中发挥领导作用外，加拿大还将受益于进一步了解导致地球重大进化步骤的潜在过程，这些步骤可以为有关地质灾害、环境保护和气候变化的政策制定倡议提供信息。

The Earth's geosphere, atmosphere, hydrosphere and biosphere interact in diverse ways at a variety of spatial and temporal scales. Studying the impacts of climate and erosion on tectonics (the study of the Earth's crust and the forces that influence it) is one of the most active research topics in the geological sciences. The Himalaya is the archetypal mountain range formed by the collision of continents, and its southern rampart is an exceptional natural laboratory to test the interactions between Earth's interior and surface processes. For example, the Indian summer monsoon plays an essential role in erosion along the Himalaya and its intensity has varied considerably since it was established some 12 million years ago. Conversely, the movement of Himalayan tectonic plates has remained fairly steady since collision between India and Eurasia began ~55 million years ago. As the same rock types are found along the entire 2000 km-wide mountain range, observed changes in surface geology are most likely due to the variation of erosion in space and time. The formation of the Himalaya is currently explained by two contrasting tectonic models that differ in their predictions for the sequence of deformation along the main structures. The rationale of this investigation is to provide a comprehensive study of the ages of the main geological structures and erosion rates, as a field-based test of the model predictions. This will provide crucial information about the coupling of deformation between middle and upper crustal levels and ultimately about the links between deep crustal deformation and surface processes. Floods, landslides, debris flows and even earthquakes are consequences of the processes that create dynamic landscapes in tectonically-active areas. Comprehending the rate and variability of such mass transport systems on the Earth's surface and understanding the Earth's response to climate changes over geologic time will lead to better hazard forecasting. In addition to taking a leadership role in the discipline, Canada will benefit from further understanding of the underlying processes responsible for the Earth's major evolutionary steps that can inform into policy development initiatives regarding geohazard, environmental protection and climate change.