Survey of Warnimont Bluff, Wisconsin, February 2020

High lake levels are reducing beach area along the Lake Michigan coastline and allowing wave action to erode the bases of coastal bluffs at the highest rate of the past 30 years. Sediment budget calculations have shown that bluff erosion is the dominant source of sand and gravel-sized particles that are mobilized into beaches and the nearshore system. Researchers have found that the leading cause of bluff erosion is shallow to intermediate depth translational landslides. Therefore, estimating lake sediment budgets depends on an understanding of the mechanisms that lead to landslide failure. This study will provide a comprehensive analysis of bluff stability for bluffs affected by landslide failure coupled with an analysis of bluff composition to determine the composition of sediment contributions of coastal bluffs to the southeast Lake Michigan sediment budget.密歇根湖（Lake Michigan）沿岸的高水位正持续缩减海滩面积，并使得波浪侵蚀海岸陡崖基部的速率达到过去30年来的峰值。沉积物收支（sediment budget）计算结果表明，海岸陡崖侵蚀是形成可迁移至海滩及近岸系统的砂、砾级颗粒的主要来源。研究人员发现，海岸陡崖侵蚀的首要诱因为浅至中等深度的平移式滑坡（translational landslides）。因此，精准估算湖泊沉积物收支，有赖于对滑坡失稳触发机制的深入认知。本研究将针对受滑坡失稳影响的海岸陡崖开展陡崖稳定性综合分析，并结合陡崖组成成分分析，以明确密歇根湖东南部海岸陡崖向该区域沉积物收支贡献的沉积物组分特征。