The topography of the eastern Southern Alps (ESA) reflects indenter tectonics causing crustal shortening, surface uplift, and erosional response. Fluvial drainages were perturbed by Pleistocene glaciations that locally excavated alpine valleys. The Late Miocene desiccation of the Mediterranean Sea and the uplift of the northern Molasse Basin led to significant base level changes in the far field of the ESA and the Eastern Alps (EA), respectively. Among this multitude of mechanisms, the processes that dominate the current topographic evolution of the ESA and the ESA-EA drainage divide have not been identified. We demonstrate the expected topographic effects of each mechanism in a one-dimensional model and compare them with observed channel metrics. We find that the normalized steepness index increases with uplift rate and declines from the indenter tip in the northwest to the foreland basin in the southeast. The number and amplitude of knickpoints and the distortion in longitudinal channel profiles similarly decrease toward the east. Changes in slope of χ-transformed channel profiles coincide spatially with the Valsugana-Fella fault linking crustal stacking and uplift induced by indenter tectonics with topographic evolution. Gradients in χ across the ESA-EA drainage divide imply an ongoing, north directed shift of the Danube-ESA watershed that is most likely driven by a base level rise in the northern Molasse basin. We conclude that the regional uplift pattern controls the geometry of ESA-EA channels, while base level changes in the far field control the overall architecture of the orogen by drainage divide migration.

中文翻译：

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大陆压头的地形：南阿尔卑斯山东部地壳变形、侵蚀和基准面变化之间的相互作用。


南阿尔卑斯山东部（ESA）的地形反映了导致地壳缩短、表面隆起和侵蚀反应的压头构造。更新世冰川作用破坏了局部高山山谷，扰乱了河流排水系统。中新世晚期地中海的干燥和北部莫拉斯盆地的隆起分别导致欧空局远场和东阿尔卑斯山（EA）的基准面发生显着变化。在众多机制中，主导当前欧空局地形演化和欧空局-东亚区排水分界的过程尚未确定。我们在一维模型中展示了每种机制的预期地形效应，并将它们与观察到的通道指标进行比较。我们发现归一化陡度指数随着抬升速率的增加而增大，从西北的压头尖端到东南的前陆盆地逐渐减小。拐点的数量和幅度以及纵向河道剖面的变形同样向东减少。 χ 变换河道剖面的斜率变化在空间上与 Valsugana-Fella 断层一致，该断层将压头构造引起的地壳堆积和隆起与地形演化联系起来。 ESA-EA 流域分水岭的 χ 梯度意味着多瑙河-ESA 分水岭正在发生向北的移动，这很可能是由莫拉斯盆地北部基准面上升驱动的。我们得出的结论是，区域隆起模式控制了 ESA-EA 通道的几何形状，而远场的基准面变化通过排水分水岭的迁移控制了造山带的整体结构。