STUDY ON OFFSHORE SEDIMENT TRANSPORT TO NYUZEN SUBMARINE CANYON, SHIMONIIKAWA COAST

Abstract

 This study investigated field surveys, hydraulic model tests and numerical simulations in order to clarify the mechanisms of offshore sediment transport to Nyuzen submarine canyon. Soundings indicated that erosion occurred from T.P. -15 m to -25 m, deeper than critical depth. sediment surveys indicated that amount of offshore sediment transport was considered to be small in deeper than T.P. -50m , judged by percentage of silt and clay. Moreover, gravel was distributed shallower than T.P. -10 m on the survey lines which have Nyuzen submarine canyon offshore. This mechanism was caused by wave height with a return period of about 5 years using hydraulic model tests and numerical simulations.