Determination of potential tsunami-induced current velocity, bathymetric change, and vessel safe zone in Tokyo Bay

这项研究的主要目的是评估东京湾内的危险，从附近的俯冲带地震产生的海啸。通过分析地震情景下海啸传播和沉积物输运的模拟结果，可以进行海啸危险性评估。我们使用Karhunen-Loeve（K-L）展开法随机生成相模海槽板块界面上的滑移分布。板块界面的几何形状是基于日本综合速度结构模型（JIVSM）。产生的滑动分布的量级为Mw 7.7至8.2，单位间距为0.1个量级（六个量级）。我们为每个震级生成了50个滑动分布，总共有300个地震场景。对于每种情况，我们使用高质量和高分辨率（1弧秒）的水深和地形数据集模拟了海啸在东京湾的传播和淹没。我们开发了一个数值模型，可以模拟海啸沙存款的厚度和粒度分布。数值模型的校准与海啸淹没高度，存款厚度和粒度分布，在岩手县沼之滨海岸周围的地形和水深数据的高质量和可靠的观测，并为2011年东北地震的震源模型。一个模型的概念与三个模型层的悬浮沉积物，存款，和母层允许模拟沉积物粒度分布和存款厚度。

The main objective of this research is to assess the hazard inside the Tokyo Bay induced from tsunamis generated by earthquakes from nearby subduction zones. The tsunami hazard assessment can be done by analyzing simulation results of tsunami propagation and sediment transportation from a set of earthquake scenarios.We randomly generated slip distributions on the plate interface of the Sagami Trough using the Karhunen‐Loeve (K‐L) expansion method. The geometry of the plate interface is based on the Japan Integrated Velocity Structure Model (JIVSM). The magnitudes of the generated the slip distributions are from Mw 7.7 to 8.2 with 0.1 magnitude unit spacing (six magnitudes). We generated 50 slip distributions for each magnitude for a total of 300 earthquake scenarios. For each scenario, we simulated the tsunami propagation and inundation in the Tokyo Bay using high-quality and high-resolution (1 arc-sec) bathymetry and topography dataset.We developed a numerical model that can simulate the thickness and grain size distribution of tsunami sand deposit. The numerical model was calibrated with high quality and reliable observations of tsunami inundation heights, deposit thickness and grain size distribution, topography and bathymetry data around Numanohama coast in Iwate prefecture, and a source model for the 2011 Tohoku earthquake. A model concept with three model layers of suspended sediment, deposit, and parent layers allows simulation of sediment grain size distribution and deposit thickness.