[MIS09-P05] On the secular change of the bottom sediment after the 2011 Tohoku-oki tsunami in Onagawa Bay
Keywords:Tsunami deposit, Onagawa Bay
Tokai University conduct, as part of Tohoku Ecosystem-Associated Marine Sciences(TEAMS), various surveys (MNB, SSS, SBP, ROV, bottom sediment survey) at Sanriku region for continue to distribution and characteristics of tsunami deposits since 2012. This time we will report on the survey conducted at Onagawa Bay located in the southern part of the Sanriku Rias coast.
In this research, as a result of the bottom sediment survey of Onagawa Bay after the 2011 Tohoku-oki tsunami, it was found that the sediment was changed from sandy to muddy environment by the effect of the tsunami.
The bottom sediment distribution map was prepared from the data of the sediment survey conducted by Tohoku University (data from 2013).
As a result, it seemed that the proportion of mud content is low. The secular change of bottom material after the 2011 Tohoku-oki tsunami in Onagawa Bay, is thought that the proportion of mud decreases over time and it is changing to sandy material.
In this research, as a result of the bottom sediment survey of Onagawa Bay after the 2011 Tohoku-oki tsunami, it was found that the sediment was changed from sandy to muddy environment by the effect of the tsunami.
The bottom sediment distribution map was prepared from the data of the sediment survey conducted by Tohoku University (data from 2013).
As a result, it seemed that the proportion of mud content is low. The secular change of bottom material after the 2011 Tohoku-oki tsunami in Onagawa Bay, is thought that the proportion of mud decreases over time and it is changing to sandy material.