Bontemps Noélie, Lacroix Pascal, Larose Eric, Jara Jorge, Taipe Edu
Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000, Grenoble, France.
Laboratoire de Géologie, Département des Géosciences, École Normale Supérieure, CNRS, UMR 8538, PSL Research University, Paris, France.
Nat Commun. 2020 Feb 7;11(1):780. doi: 10.1038/s41467-020-14445-3.
In tectonically active mountain belts, landslides contribute significantly to erosion. Statistical analysis of regional inventories of earthquake-triggered-landslides after large earthquakes (Mw > 5.5) reveal a complex interaction between seismic shaking, landslide material, and rainfall. However, the contributions of each component have never been quantified due to a lack of in-situ data for active landslides. We exploited a 3-year geodetic and seismic dataset for a slow-moving landslide in Peru affected by local earthquakes and seasonal rainfalls. Here we show that in combination, they cause greater landslide motion than either force alone. We also show the rigidity of the landslide's bulk clearly decreasing during Ml ≥ 5 earthquakes. The recovery is affected by rainfall and small earthquakes (Ml < 3.6), which prevent the soil from healing, highlighting the importance of the timing between forcings. These new quantitative insights into the mechanics of landslides open new perspectives for the study of the mass balance of earthquakes.
在构造活动活跃的山区，山体滑坡对侵蚀作用有显著贡献。对大地震（Mw > 5.5）后地震触发山体滑坡的区域清单进行统计分析，揭示了地震震动、滑坡物质和降雨之间复杂的相互作用。然而，由于缺乏活跃滑坡的现场数据，每个组成部分的贡献从未被量化过。我们利用了一个为期3年的大地测量和地震数据集，该数据集针对秘鲁一个受当地地震和季节性降雨影响的缓慢移动的滑坡。在这里，我们表明，它们共同作用导致的滑坡移动比单独任何一种作用力都更大。我们还表明，在Ml ≥ 5级地震期间，滑坡整体的刚度明显下降。恢复过程受到降雨和小地震（Ml < 3.6）的影响，这些因素阻碍了土壤愈合，突出了作用力之间时间同步的重要性。这些关于滑坡力学的新的定量见解为地震质量平衡研究开辟了新的视角。
