Sand grain shape analysis by Elliptic Fourier-Principal Component Analysis: proposal of an index to determine paleo-wave energy

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05319
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Waseda University
• Principal Investigator: Ohta Tohru 早稲田大学, 教育・総合科学学術院, 教授 (40409610)
• Research Collaborator: HASHIMOTO Tomoko ; SEKI Sho
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 粒子形状 / 前浜堆積物 / フーリエ分析 / 主成分分析

Outline of Final Research Achievements

This study investigated the relationship of foreshore grain shapes and wave/wind power. Principal component analysis revealed that PC1 represents wave power and it showed a positive correlation with roundness index, and foreshores facing Pacific and Sea of Japan showed contrasting values. Therefore, this latent value indicates that grains tend to be rounded in large oceans that are frequently attacked by swells. PC2 represents wind power and showed positive correlation with smoothness index, and showed high values where aeolian dunes are developed. Therefore, this latent value illustrates the degree of development of strand plain and, that in such environment, grain surfaces tend to be smooth. Application of the present result enables to predict the size of the ocean and presence of aeolian dunes simply from the analysis of grain shapes.

Free Research Field

地質学