The geosphere dynamics near Earth's surface is a key scientific issue for understanding how Earth system works. However, the specific mechanisms underlying the interplay between these geospheres still remain unclear. Here, we take the eastern Himalayan syntaxis, the most typical region undergoing ferocious geosphere interplay on the planet, as our primary research area. We incorporated a topography-dependent precipitation model into traditional geomorphological-thermomechanical modelling and conducted over 200 experiments to investigate the interplay between climate, tectonics, and surface processes during the evolution of the orogenic wedge. The results show that a distinct type of orogenic wedge emerges when the convergence rate and average precipitation fall within specific ranges determined by the crustal geothermal field. Within this type of orogenic wedge, a sustained, stationary, localized and relatively rapid erosion process can be established on the windward flank. This can further induce sustained and rapid uplift of rocks, exhumation and deformation, forming a large-scale antiform, which exhibits a certain degree of similarity to the eastern Himalayan syntaxis. We propose that the formation of the eastern Himalayan syntaxis share this similar mechanism. Our analysis of the results indicates that the influences of climatic forcing, tectonic forcing, and geothermal field on the evolution of orogenic wedge can be integrated into a single parameter (EF), and we propose that 0.24≤EF≤0.45 is a necessary condition for the development of a syntaxis, which provides a quantitative constraint on the formation of a syntaxis for the first time.

中文翻译：

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喜马拉雅东部气候、构造和地表过程耦合的数值模拟


地球表面附近的地圈动力学是理解地球系统如何运作的关键科学问题。然而，这些地圈之间相互作用的具体机制仍然不清楚。在这里，我们以东部喜马拉雅 syntaxis 作为我们的主要研究领域，这是地球上最典型的经历凶猛地圈相互作用的区域。我们将依赖于地形的降水模型纳入传统的地貌热机械建模中，并进行了 200 多次实验，以研究造山楔形演化过程中气候、构造和地表过程之间的相互作用。结果表明，当辐合速率和平均降水量落在地壳地热场确定的特定范围内时，会出现一种不同类型的造山楔形。在这种类型的造山楔形中，可以在迎风侧翼建立一个持续的、静止的、局部的和相对快速的侵蚀过程。这可以进一步诱发岩石的持续快速隆起、挖掘和变形，形成一个大规模的反形式，它与东部喜马拉雅 syntaxis 表现出一定程度的相似性。我们提出东部喜马拉雅语法的形成具有类似的机制。我们对结果的分析表明，气候强迫、构造强迫和地热场对造山楔形演化的影响可以整合到单个参数 （EF） 中，我们提出 0.24≤EF≤0.45 是句法发展的必要条件，首次为句法的形成提供了定量约束。