Author(s): Yasuyuki Baba; Kiyoshi Uchiyama
Linked Author(s): Yasuyuki Baba
Keywords: Field observation; Boring core sample; Vertical sediment distribution
Abstract: This paper shows some field observation results on the bottom profile and vertical grain size distributions in Joetsu-Ogata coast, Japan. The field observation have been conducted in Aug2010, the following activities are performed: (1) bottom profile measurement by GPS sounder, (2) sediment sampling (on the bottom surface) and (3) sampling of boring cores by vibro core sampler. It is found from the results that the qualitative change of sediment is recognized although the bottom profile in the observed area would be under quasi-stable condition. The vertical sediment distribution is investigated by using the core samples at 9 points with different depth. The cross-sectional distribution of D50 is obtained through the grain size analyses. It is expected from the comparison of the sediment composition that the disturbance of vertical sediment structure occurred at least 50–70cm below the bottom surface under the storm conditions in the previous winter season.
Year: 2012