Sedimentation of Tidal Currents

潮流的沉积

基本信息

批准号：
01540624
负责人：
MAKINO Yasuhiko
金额：
$ 0.64万
依托单位：
Ibaraki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

In the last year of my project, I did research on sedimentation of intertidal sandbars in the Ariake Sea, and Pleistocene intertidal sediments near Ajigaura beach along the Pacific coast.1. In the Ariake Sea (Bay), muddy tidal flat sediments are widely distributed at the inner part, and sandy tidal flat sediments are developing along the coast of the outer part in Kumamoto Prefecture. At Toguchiura beach, the Uto Peninsula, we can see ten and more ridges of intertidal sandbars. Their ridges are sinuous in phase and subparallel to the beach. Many wave ripples are constructed on the intertidal sandbars by waves in a wind during high tide. The crest line of wave ripples is oblique to the ridge of these sandbars.The peaked crests of wave ripples on a seaward slope of these bars are eroded with weak wave action just before emergence of wave ripples, and become rounded or flattened. Wave ripples on a landward slope are very little deformed by waves. As the result, the attitude of wave ripples is characteristics at the position of intertidal sandbars. Their difference is very important as a criterion for discriminating the seaward direction.2. We found out Pleistocene step sediments at Ajigaura beach. When a longshore bar moves to the beach under fair weather, it becomes a beach-attached (welded) bar. The backrushing water sliding down the surface of the beach deforms welded bar sediments to make step. We can know the step-base depth (h) from the step depth (Z : the thickness of step sediments) at that time ; h=1.8 Z. As description on step sediments is very few, I am going to describe on step sediments.

在项目的最后一年中，我研究了Ariake海中潮间带沙洲的沉积，以及太平洋海岸沿Ajigaura海滩附近的更新世的潮汐间沉积物。1。在阿里亚克（Ariake）海（海湾）中，泥泞的潮汐扁平沉积物在内部广泛分布，而沙质潮汐平坦的沉积物正在库曼莫托县外部沿海沿海发育。在UTO半岛的Toguchiura海滩，我们可以看到十个和更多的潮间带沙洲山脊。他们的山脊在相位弯曲，距离海滩相比。在高潮期间，通过风中的波浪在潮间带的沙洲上构建了许多波浪纹波。波浪纹波的波峰线倾斜到这些沙子的山脊上。在这些条形的沿海斜率上的波纹峰峰在波浪涟漪出现之前被弱波动侵蚀，并变成圆形或扁平。陆上斜坡上的波浪涟漪几乎没有被波浪变形。结果，波浪波动的态度是在潮间带沙下位置的特征。它们的差异非常重要，作为区分海方向的标准。2。我们在阿吉古拉海滩（Ajigaura Beach）找到了更新世的阶梯沉积物。当漫长的酒吧在天气晴朗的天气下移至海滩时，它变成了一个附着在海滩的酒吧（焊接）酒吧。倒退的水从海滩的表面滑落，使焊接的钢筋沉积物变形，以迈出一步。我们可以从当时的步进深度（Z：台阶沉积物的厚度）中知道阶梯深度（h）； h = 1.8 z。作为台阶沉积物中的描述很少，我将在台阶沉积物上描述。