학술논문

Relationships Between Physical Indices and Hardness of Marine Bottom Sediment Offshore of the Kaetsu Region, Niigata Prefecture / 新潟県下越陸棚域海底における泥底及び砂底の底質硬度と物性指標の関係
Document Type
Journal Article
Source
日本水産工学会誌 / Journal of Fisheries Engineering. 2010, 47(1):63
Subject
Digital force gauge
Hardness
Penetrometer for soft soil
Vane tester
Water content
デジタルフォースゲージ
ベーンテスター
含水比
汚泥用硬度計
硬度
Language
Japanese
ISSN
0916-7617
2189-7131
Abstract
Characteristics of the bottom sediment are important factors for burrowing benthic animals. Several types of indices have been proposed to evaluate the sediment characteristics, however, relationships between these indices have rarely been considered and inconvenience due to problems related to the inability to conversion between these indices is increasingly recognized. The aim of this study is to seek practical candidates for conversion between physical property indices and hardness indices. As the physical property indices, water content, actual density, true density and mud content were obtained from samples of marine bottom sediment from 50〜100m depth offshore of the Kaetsu region, Niigata Prefecture. Three kinds of hardness indices measured by a digital force gauge (DFG), a vane tester (VT), and a penetrometer (PE) and the ignition loss were obtained from the same sediment samples and their relationships investigated. For muddy sediment samples, measurements of DFG showed significant correlations with several other indices, while measurements of PE did not show any significant correlations with these physical property indices. Thus, estimation from the physical property indices should focused on DFG measurements within the three hardness indices. The other hardness indices (VT and PE), however, have a feature to represent the hardness at the marginal surface layer of the sediment, which is more important for shallow burrowing benthos. For sandy sediment samples, more samples should be included in further analyses to detect significant relationships between the indices.