Recharge response and kinematics of an unusual earthflow in Liechtenstein

Abstract Understanding landslide behavior over medium and long timescales is crucial for predicting hazard constructing accurate landscape evolution models. The of landslides in soil that undergo periodic displacements, termed earthflows or compound slides, especially difficult to forecast at these timescales. This because velocities can increase by orders magnitude annual decadal timescales, due processes such as changing recharge conditions, erosion the toe, retrogression head. In this paper, we provide a detailed analysis Schlucher landslide, an unusual earthflow perched above village Malbun, Liechtenstein. had been displacing 10 20 cm/year until 2015, when displacements on order 2 m/year occurred from 2016 2018. These large damaged mitigation measures, caused numerous surface deformation features, threatened local population downstream earthflow. has unusually monitoring record, with displacement climatic data available since 1983. We analyze nearly 40-year time series estimate snowmelt rainfall, its correlation displacement. also recently collected, high-resolution subsurface understand response recharge, kinematics through time, catastrophic failure potential. find interannual be explained variations recharge; however, surges recurrence times tens years must other mechanisms. particular, into during recent acceleration (2016 2018) was not anomalously high. Instead, argue loss internal strength responsible period, mechanism should considered forecasting surge potential certain slides.