A Long-Traveling Landslide in Deep Snow Conditions: A Case Study of the Tatsunokuchi Landslide Induced by the 2011 North Nagano Prefecture Earthquake
A Long-Traveling Landslide in Deep Snow Conditions: A Case Study of the Tatsunokuchi Landslide Induced by the 2011 North Nagano Prefecture Earthquake
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DOI：
10.1007/978-3-642-32238-9_21
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S. Yamasaki;Hidehisa Nagata
中科院分区：
文献类型：
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作者：
S. Yamasaki;Hidehisa Nagata
2011年长野县北部地震（MJMA6.7）发生在日本的一个深雪地区，该地区每年的积雪通常超过2米。地震引发的山体滑坡涉及大量积雪。我们研究了残留的地形，以推断这些滑坡之一，龙之口滑坡，发生在深雪条件下的滑坡过程。所研究的滑坡有一个流离失所的质量，包括大量的雪，旅行了很长的距离，并破坏了更广泛的地区比传统的等距滑坡。结果表明，滑坡过程为：5 × 104 m3的岩体崩塌，岩屑进入大量积雪中，形成雪与岩屑的混合物，并在积雪上移动。最终，流离失所的群众推开了附近的积雪，从而扩大了受损区域。具有相对较低比例的碎片的移位质量可能具有足够低的密度以具有浮力，因此容易在雪上行进。我们使用Lenau方法估计滑坡的速度，并获得最大速度为14 m/s。我们的观察和明确的滑坡过程表明，如果发生在深雪条件下，滑坡将破坏比预期更广泛的区域。
The 2011 north Nagano Prefecture earthquake (MJMA6.7) occurred in a deep snow area of Japan that typically has an annual snow cover of more than 2 m. The earthquake induced landslides involving abundant snow. We examined remnant topographies to deduce the landsliding process of one of these landslides, the Tatsunokuchi landslide, which occurred in deep snow conditions. The studied landslide had a displaced mass that included much snow, traveled a long distance, and damaged a wider area than conventional isometric landslides. Our results indicated the following landsliding process: the landslide occurred by the collapse of a rock mass of 5 × 104m3, rock debris plunged into the abundant snow, a mixture of snow and rock debris formed, and the mixture then traveled on top of snow. Eventually, the displaced mass pushed out nearby snow and thus extended the damage area. The displaced mass having a relatively low proportion of debris probably had a low enough density to be buoyant and therefore easily traveled on top of snow. We estimated the velocity of the landslide using Lenau’s method and obtained a maximum velocity of 14 m/s. Our observations and the clarified landsliding process suggest that landslides will damage a wider area than expected if they occur in deep snow conditions.