Study on mechanism of landslide-induced tsunami by sedimentrological approach

沉积学方法研究滑坡引发海啸的机制

• 批准号: 12574016
• 负责人: IMAMURA Fumihiko
• 金额: $ 9.41万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12574016/
• 关键词: Landslide tsunami; historical tsunami; sand sedimentation; field study and hydraulic experiments; 発生メカニズム; 波数分散性; 堆積物

This study aims to study the mechanism of landslide-induced tsunami by sedimentrological approach using the tsunami sedimentation. A tsunamigenic sediment layer has been discovered in fluvio-alluvial sequences on the northern coast of the Marmara Sea, northwestern Turkey. The layer is consisting of unsorted silty coarse sand including landsnails and charcoal fragments. The AMS radiometric ages of the shells have been estimated at around BC400, AD300, AD400, and AD1,000. It is proposed that a tsunami occurred in the Marmara Sea in the middle of 11th century and invaded the fluvial plains. The older fossils were derived from the underlying horizons, and we suggest that buoyancy materials such as landshells and charcoals were isolated from liquefied sediments durlng submarine sliding. Slope failing of coastal blocks triggered by fault movement generated tsunamis, which might have transported floating materials to the backshore. The simulation model for tsunamis caused by landsliding and d … More ebris flow is proposed and compared with the result from the hydraulic experiment model with an open-channel. We applied nonlinear long-wave theory integrated over a layer with non-horizontal bottom/interface as the governing equation for the numerical model. We assume hydrostatic pressure distribution, and uniform density and velocity distributions in each layer. For the case of tsunami generation by landslide, the sea water is modeled as an upper layer for wave generation and propagation, and the landslide is modeled. We used the staggered leap-frog scheme for the linear terms and the up-wind scheme for the nonlinear terms in this study. The leap-frog scheme is a central difference scheme with a truncation error of the second order. Three parameters/coefficients of the bottom friction, the horizontal viscousity and the interactive force between landslide and tsuami rushing into water are examined through comparison with the results of hydraulic experiments. We found that the Manning coefficient of 0.12 and horizontal viscousity of 0.01 are recommended for landsliding in this study. Although the interactive force is significantly important for a tsunami generation, a more detail analysis is required to determine a value of its coefficient. Less

本研究旨在利用海啸沉积作用，以沉积学的方法探讨滑坡引发海啸的机制。在土耳其西北部的马尔马拉海北方海岸的河流-冲积层中发现了一个海啸沉积层。该层由未分选的粉质粗砂组成，包括陆蜗牛和木炭碎片。根据AMS的辐射年龄估计，这些贝壳的年龄分别为公元前400年、公元300年、公元400年和公元1，000年。据推测，11世纪中叶马尔马拉海曾发生过海啸，并侵入了河流平原。较老的化石来自下伏层位，我们认为，浮力材料，如陆壳和木炭被隔离从液化沉积物dureneous海底滑动。断层运动引发的海岸块体的斜坡坍塌产生了海啸，海啸可能将漂浮的物质带到了后海岸。建立了滑坡和滑坡引发海啸的模拟模型， ...更多信息 并与明渠水力学模型试验结果进行了比较。我们采用非线性长波理论集成了一个层与非水平的底部/界面作为控制方程的数值模型。我们假设流体静压分布，以及均匀的密度和速度分布在每一层。对于滑坡产生海啸的情况，海水被模拟为用于波的产生和传播的上层，并且对滑坡进行模拟。在本研究中，线性项采用交错蛙跳格式，非线性项采用迎风格式。蛙跳格式是一种具有二阶截断误差的中心差分格式。通过与水力学试验结果的对比，对滑坡的底摩擦力、水平粘性系数和滑坡与海啸入水的相互作用力等3个参数进行了研究。我们发现，曼宁系数为0.12和水平粘性为0.01，建议在本研究中的滑坡。虽然相互作用力对于海啸的产生是非常重要的，但是需要更详细的分析来确定其系数的值。少

项目成果

今村文彦 ら: "1999年8月トルコ・コジャエリ地震に伴って発生した津波の現地調査と数値解析"海岸工学論文集. 47巻. 331-335 (2000)

Fumihiko Imamura 等人：“1999 年 8 月土耳其科贾埃利地震引发的海啸的现场调查和数值分析”海岸工程论文，第 47 卷，331-335 (2000)。

MINOURA et al.: "Discovery of Minoan tsunami deposits"Geology. VOl.28,No.1. 59-62 (2000)

MINOURA 等人：“米诺斯海啸沉积物的发现”地质学。

Imteaz,M.A. and F. Imamura: "Analytical solution and numerical model for the interface in a stratified long wave system"Science of Tsunami Hazards. 19,1. pp.39-54 (2001)

伊姆泰兹，文学硕士

IMTEAZ, IMAMURA: "Analytical solution and numerical model for the interface in a stratified long wave system"Science of Tsunami Hazards. Vol.19,No.1. 39-54 (2001)

IMTEAZ、IMAMURA：“分层长波系统界面的解析解和数值模型”海啸灾害科学。

Minoura,K., F. Imamura, U. Kuran, T. Nakamura, G. A. Papadopoulos, T.Takahashi, A. C. Yalciner: "Discovery of Minoan tstmami deposits"Geology. 28,1. pp.59-62 (2000)

Minoura,K.、F. Imamura、U. Kuran、T. Nakamura、G. A. Papadopoulos、T.Takahashi、A. C. Yalciner：“米诺斯 tstmami 矿床的发现”地质学。