Sediment flux from the Zhoushan Archipelago,eastern China

摘要

Knowledge of the sediment flux derived from different sources is critical for interpreting the sedimentary records associated with large river sedimentary systems.For the Changjiang River system,previous studies hardly focused on the sediment load from the adjacent Zhoushan Archipelago (ZA).Based on four prediction models,aiming to improve the understanding of the sediment load from the ZA during the Holocene,we show that the predicted sediment flux of the ZA ranges from ～0.7 to 26.5 Mt·yr-1,with an average value of 10.7 Mt·yr-1,and the islands with a relatively large area or high relief contribute greatly to the total flux.This sediment load is an order of magnitude lower than that of the Changjiang River,but it is similar to those of the local small rivers.Located in the core area of the southward dispersal path of the Changjiang River plume,the ZA also influences the sediment transport into Hangzhou Bay and over the Zhejiang-Fujian coastal seas.On the Holocene temporal scale,e.g.,for the period from 6 ka BP to 2 ka BP,the sediments discharged from the ZA had a considerable effect on the shelf sedimentary system.This study provides evidence for an important role an archipelago can play in terms of sediment supply and transport in coastal and inner continental shelf regions.