基于半球形瞬时撞击坑的近地天体撞击诱发海啸的深水波模型

Deep Water Wave Model of Near-Earth Object Impact Induced Tsunami Based on Hemispherical Instantaneous Crater

采用初始扰动为半球形瞬时撞击坑作为初始条件,建立了近地天体撞击诱发海啸的深水波模型,应用到特定情形下(小行星直径为140 m、撞击速度与密度采用车里雅宾斯克陨击参数、撞击区域平均海洋深度采用太平洋平均水深4 km)研究了近地天体撞击海洋诱发海啸的波高最大值随距离和时间的演化情况.对比不同的瞬时撞击坑模型和传播模型对海啸波高的影响发现:半球形瞬时撞击坑诱发的海啸危害比抛物形瞬时撞击坑更大;相对于深水波模型,浅水波模型给出撞击诱发海啸的规模较大;对于中等尺寸(直径在几百米范围内)的小行星,研究其撞击海洋诱发海啸,更适合采用瞬时撞击坑形状为半球形的深水波模型.

This article uses the initial disturbance of a hemispherical instantaneous impact crater as the initial condition to establish a deep water wave model for tsunamis induced by near-Earth object impacts.Applied to specific situations(Asteroid with a diameter of 140 m,impact velocity and density using Cheryabinsk impact parameters,average ocean depth in the impact area using Pacific average depth of 4 km),the evolution of the maximum wave height of near-Earth object impact induced tsunamis with distance and time was studied.By comparing the effects of different instantaneous impact crater shapes and impact models on the wave height of impact induced tsunamis,it was found that the tsunami harm caused by hemispherical instantaneous impact craters is greater than that caused by parabolic instantaneous impact craters;Compared to the deep water wave model,the simulation of the shallow water wave model shows a larger scale of tsunamis;For medium-sized asteroids with a diameter within a few hundred meters,it is more suitable to use a deep water wave model with an instantaneous impact crater shape of a hemisphere to study their impact on the ocean induced tsunami.