Sediment transport in the Yellow Sea and East China Sea

Eight survey cruises in different seasons have been conducted in the Yellow Sea (YS) and East China Sea (ECS) during the period from 2000 to 2008. Suspended sediment concentration (SSC) and hydrological data were collected during each cruise. Data analysis showed that total suspended sediment mass was approximately 0.18 × 109 tons in the surveyed area during spring and autumn seasons. Highly turbid waters were found in the shallow waters between the Subei coast, the Changjiang estuary and the Zhejiang coast with seasonal variations.The investigation provided convincing evidence that suspended sediments were transported from the Subei coast and the southern entrance of the Yellow Sea Trough to the central YS. Muddy patches were found at the sea bed when tidal currents were too weak to erode the bottom sediments and water column stratification and eddies provided favorable conditions for trapping the fine-grained suspended sediments.The investigation indicated that the different front may have different effect on sediment transport during different seasons. The front between the Yellow Sea Cold Water and the coastal water in the Subei coast appeared to trap the high SSC sediments on the shallow water side of the front. During summer, the front along the Zhejiang coast seemed to prevent suspended sediments from transport across the front due to circulation in the front zone and upwelling along the Zhejiang coast. During winter, sediments were likely transported across the front to the central continental shelf of the ECS with the help of the downwelling and lateral Ekman transport driven by monsoon winds.

► We collect abundant in-situ data from 8 cruises during 2000–2008.
► We discuss the seasonal sediment transport and possible mechanism.
► Suspended sediments are transported from the Subei coast to the central Yellow Sea.
► A new explanation is given on the formation of muddy patches in the region.
► The different front may have different effect on sediment transport during different seasons.