Subaquatic mass movements are common in marine and lacustrine environments, but due to their barely predictable nature, direct observations of these processes are limited so that knowledge is only indirectly obtained by investigating the resulting mass-transport deposits (MTDs). Most research focuses on the most common frontally emergent slides, fast-moving events able to generate turbidity currents and tsunamis. Geohazards of frontally confined slides and mechanisms behind their typical fold-and-thrust deformation structures are however still poorly understood.

We investigate frontally confined MTDs in Lake Lucerne (Switzerland) by integrating bathymetric and high-resolution seismic data with geotechnical information derived from in situ Cone Penetrometer Tests and short core analysis. Investigated MTDs consist of three units: i) a mass-slide deposit, located at the base of the slope consisting of a coherent slope sequence, ii) a fold-and-thrust system developed in basin sediments, and iii) an overrunning mass flow deposit, consisting of remolded slope sediments. The deformed and thrusted basin sediments show higher undrained shear strength compared to the undisturbed basin sequence. We propose that this strengthening is caused by lateral compression leading to fluid expulsion in the high-plasticity basin sediments by the bulldozing sliding mass. Relative kinematic indicators document that the fold-and-thrust deformation structures occur rapidly. Thus, they should be considered in tsunami hazard analysis. Furthermore, our data highlight that the slope angle of the gliding surface and basin topography are key controlling factors for slope stability and propagation of basin-plain deformations, respectively. Our integrated study supports and refines propagation models proposed in marine environments, revealing the potential of investigating smaller-scale easier-to-access MTDs in lakes.

亚水族运动在海洋和湖相环境中很常见，但是由于它们几乎不可预测的性质，对这些过程的直接观察受到了限制，因此只能通过研究由此产生的质子传递沉积物（MTDs）间接获得知识。大多数研究都集中在最常见的正面出现的幻灯片上，即能够产生浑浊流和海啸的快速移动事件。然而，人们仍然很少了解在典型的褶皱和冲断变形结构后面的前部受限制的滑坡和机制的地质灾害。

我们通过将测深和高分辨率地震数据与从原位圆锥渗透仪测试和短岩心分析获得的岩土信息相集成，来研究卢塞恩湖（瑞士）的前部受限MTD。研究的MTD由三个单元组成：i）位于斜坡底部的质量滑移沉积物，由连贯的斜坡序列组成； ii）流域沉积物中形成的褶皱-冲断系统，iii）流动质量超支沉积物，由重塑的斜坡沉积物组成。与未扰动的盆地序列相比，变形和逆冲的盆地沉积物显示出更高的不排水抗剪强度。我们认为这种加强是由于侧向压缩引起的，而这种横向压缩导致高塑性盆地沉积物中的流体被推土滑动块驱逐。相对运动学指标表明，褶皱和推力变形结构发生得很快。因此，在海啸危害分析中应考虑这些因素。此外，我们的数据表明，滑动面的倾斜角和盆地的地形分别是边坡稳定性和盆地平原变形传播的关键控制因素。我们的综合研究支持并完善了在海洋环境中提出的传播模型，从而揭示了研究湖泊中较小规模易于访问的MTD的潜力。