Advances in Computed Tomography for Geomaterials: GeoX 2010

Assessment of Time-Space Evolutions of Intertidal Flat Geo-Environments Using an Industrial X-ray CT Scanner

F. Yamada¹ — A. Tamaki² — Y. Obara³

¹Kumamoto University, Graduate School of Science and Technology 2-39-1 KurokamiKumamoto [e-mail]

 

²Nagasaki University, Faculty of Fisheries 1-14 BunkyoNagasaki [e-mail]

 

³Kumamoto University, Graduate School of Science and Technology2-39-1, KurokamiKumamoto [e-mail]

ABSTRACT. An industrial x-ray computed tomography (CT) scanner was used to investigate the time-space evolutions of vertical sediment structures in an intertidal flat with non-destructive conditions, at the mouth of the Shirakawa river, Japan. Seasonal sediment core samples were collected over one year at two locations. One location was Manila clam (Ruditapes philippinarum)-dominant, and the other clam non-dominant. Reconstructed three-dimensional images using Hounsfield Units (HU) demonstrated that water retention volumes in the intertidal sediment in the clam-dominant area existed up to 4 cm below the sediment surface. The CT results revealed that low-bulk density regions below the water-sediment interface are necessary for the survival of the Manila clam. Moreover, the shell hash composition of the substrate appeared to be related to the clam’s distribution.

 

KEYWORDS: Manila clam, biogenic structure, water retention, shell hash, industrial x-ray CT

1. Introduction

The Manila clam, ...