Destructive landslides were triggered by the 6.7 M_w Eastern Iburi earthquake that struck southern Hokkaido, Japan, on 6 September 2018. In this study, we carried out 1-D inversion analysis of one of the shallow landslides near the epicenter using a Bing debris-flow model. At this site, the slope failure comprised cover soil with an initial down-slope length of ~ 80 m and a thickness of ~ 7 m on a slope with < 20° dip. The landslide moved southeastward with a run-out distance of ~ 100 m. Inversion analysis of the post-failure deposit geometry was conducted with the Markov Chain Monte Carlo method (MCMC) to optimize the Bingham rheological parameters of the debris. The analysis reproduced several features of the deposit geometry with a yield stress of ~ 1500 Pa and dynamic viscosity of 800–3000 Pa s. The results suggest that the shallow landslide can be approximated by the flow of a viscoplastic fluid with high-mobility debris and a maximum frontal velocity of 6–9 m/s, with a flow duration of 2–4 min.

6.7 M _w引发破坏性滑坡2018年9月6日，日本北海道南部发生东部伊布里地震。在这项研究中，我们使用Bing泥石流模型对震中附近的浅层滑坡之一进行了一维反演分析。在该位置，边坡破坏包括覆盖的土壤，其初始下坡长度为〜80 m，倾斜度为<20°的斜坡上的厚度为〜7 m。滑坡向东南移动，跳动距离约为100 m。使用马尔可夫链蒙特卡洛方法（MCMC）对破坏后沉积物的几何形状进行反演分析，以优化碎片的宾厄姆流变参数。该分析再现了沉积物几何形状的几个特征，其屈服应力约为1500 Pa，动态粘度为800-3000 Pa s。