The recent San Eduardo Landslide (SEL), reactivated on the nighttime of September 20, 2018, is hypothesized as the lowest part of a large-scale deep-seated gravitational slope deformation (DSGSD) covering an area not less than 45 km 2 . Based upon remote sensing analysis through aerial photography, accompanied by fieldwork, this work attempts to identify the morphostructural features developed after reactivation of the SEL, as well as relict features upslope indicating active sagging of the adjacent mountain slopes. A preliminary segmentation of the SEL into three zones (SEL-1 to SEL-3) is proposed in order to describe the spatial distribution of extensional (e.g., uphill-facing scarps, trenches), compressional (toe bulging), and shear zones within the slid mass. To complement the geomorphological approach, displacement vectors and motion rates were derived by comparing a 5-month time series of free-cloud Sentinel 2 imagery acquired from September 2018 to February 2019. This approach helps to identify a peak motion rate of > 4 m/day in zones SEL-2 (between September 18 and 28, 2018) and SEL-3 (between September 8, 2018, and October 8, 2018). By February 2019, the motion rate decreased to less than 30 cm/day. The potential mechanisms explaining the triggering/reactivation of the large slope deformation observed are the cumulative displacement on a shale-dominated slope, and the high topographic stresses expected for this high-relief area in the Colombian Eastern Cordillera. Finally, this work explores the geomorphological evidence of a second DSGSD (sackung type) in the area, which in turn suggests that gravitational deformation is probably a more common deformation mechanism in the range than previously considered.

中文翻译：

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San Eduardo 滑坡（哥伦比亚东部山脉）：深层重力斜坡变形的重新激活

最近的圣爱德华多滑坡 (SEL) 在 2018 年 9 月 20 日夜间重新激活，被假设为覆盖面积不小于 45 km 2 的大规模深部重力斜坡变形 (DSGSD) 的最低部分。基于航拍遥感分析和实地考察，这项工作试图确定 SEL 重新激活后形成的形态结构特征，以及表明相邻山坡活动下垂的上坡遗迹特征。建议将 SEL 初步分割为三个区域（SEL-1 到 SEL-3），以描述拉伸（例如，面向上坡的陡坡、海沟）、压缩（趾部凸出）和剪切带的空间分布。滑动的质量。为了补充地貌学方法，通过比较从 2018 年 9 月到 2019 年 2 月获取的自由云 Sentinel 2 图像的 5 个月时间序列，得出位移向量和运动速率。这种方法有助于识别 SEL-2 区域中 > 4 m/天的峰值运动速率（2018 年 9 月 18 日至 28 日之间）和 SEL-3（2018 年 9 月 8 日至 2018 年 10 月 8 日之间）。到 2019 年 2 月，运动速度下降到不到 30 厘米/天。解释所观察到的大斜坡变形的触发/重新激活的潜在机制是页岩为主的斜坡上的累积位移，以及哥伦比亚东科迪勒拉高地势地区预期的高地形应力。最后，这项工作探索了该地区第二个 DSGSD（sackung 类型）的地貌证据，