Landslide mobility refers to how far and fast a landslide can move downslope. It controls landslide impact areas and damage power. Highly mobile landslides are often initiated on slopes steeper than 30°. However, on 18 December 2023, an earthquake-induced landslide (35°52′54″N, 102°51′10″E) exhibited extraordinary mobility, with an overall travel angle of 1.5°, breaking an on-land landslide record. The landslide originated on a gentle slope (3.6°), eroded an earth dam along its travel path, and finally destroyed 51 houses and claimed 20 lives. Remote sensing and field surveys were conducted to provide morphological characteristics of the hazard chain. A numerical program, EDDA (Erosion–Deposition Debris Flow Analysis), was employed to reproduce the flow dynamics and investigate the causes of hypermobility. The findings reveal three primary causes of hypermobility: (1) liquefaction of the saturated silty loess stratum due to the combined effects of irrigation activity and seismic loading, (2) the loose and macro-pore structure of loess, and (3) confined topography and icy channel bed. The mechanisms revealed have broad implications for understanding fluidized mass movements on gentle slopes in seismically active regions.

中文翻译：

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灾难性地震引发的黄土滑坡的过度活动


滑坡流动性是指滑坡可以向下移动的距离和速度。它控制着山体滑坡的影响区域和破坏力。高度移动的滑坡通常始于陡峭超过 30° 的斜坡上。然而，在 2023 年 12 月 18 日，地震引发的滑坡（35°52′54“N，102°51′10”E）表现出非凡的流动性，整体移动角度为 1.5°，打破了陆地滑坡记录。山体滑坡起源于一个平缓的斜坡 （3.6°），沿途侵蚀了一座土坝，最终摧毁了 51 座房屋，夺走了 20 条生命。进行了遥感和实地调查，以提供灾害链的形态特征。采用数值程序 EDDA（侵蚀-沉积泥石流分析）来重现流动动力学并调查过度活动的原因。研究结果揭示了过度移动的三个主要原因：（1） 由于灌溉活动和地震载荷的综合影响，饱和粉质黄土层液化，（2） 黄土的松散和大孔结构，以及 （3） 受限地形和冰冻河床。揭示的机制对于理解地震活跃地区缓坡上的流化质量运动具有广泛的意义。