厦门大学学报（自然科学版）2025，Vol.64Issue(3)：446-460,15.DOI:10.6043/j.issn.0438-0479.202411014
渤、黄、东海7 000年以来海岸线和海底沉积物厚度的演变
Evolution of coastline and seafloor sediment thickness of the Bohai,Yellow and East China Seas over the past 7 000 years
摘要
Abstract
[Objective]Since the maximum Holocene transgression,the western coasts of the Bohai,Yellow,and East China Seas have undergone significant changes,leading to the development of various sedimentation systems on the continental shelves.Changes in coastline and water depth have altered the hydrodynamic processes in the Bohai,Yellow,and East China Seas,subsequently impacting sediment transport and aquatic ecosystems.However,a comprehensive understanding of the evolution of coastlines and seabed sediments in these regions over the past 7 000 years has not been reconstructed.This study aims to establish a dataset of ancient coastlines and sediment thickness in the Bohai,Yellow,and East China Seas over the past 7 000 years,thereby providing essential data support for the investigation of ancient marine environments and sedimentary processes.[Methods]Previous studies have reconstructed the Holocene coastlines of the Bohai Sea and the western coasts of the Yellow and East China Seas.However,these investigations have primarily focused on specific regions.In this study,we identified ancient coastlines from 12 distinct time periods in the northern Jiangsu and Yangtze River Delta regions,which encompass the longest coastline within the study area.Subsequently,we established the corresponding coastlines in adjacent regions,resulting in a comprehensive reconstruction of the coastlines for the Bohai Sea and the western shores of the Yellow and East China Seas across various time periods.Additionally,we collected a total of 164 long sediment cores and 296 shallow sediment cores.Utilizing the age-thickness data obtained from these sediment cores,we estimated the sediment thickness for each paleocoastline period and interpolated this sediment thickness across the Bohai Sea and the western Yellow and East China Seas to delineate the distribution of bottom sediment thickness.[Results]Following the maximum Holocene transgression,the coastlines of Bohai Bay and Laizhou Bay progressively advanced seaward.This process stabilized after the diversion of the Yellow River during the Song Dynasty.The modern Yellow River Delta began to form after 1855,when the river changed its course and entered the Bohai Sea,resulting in the establishment of the present coastline.The epeirogenic process of coastal plain in central northern Jiangsu occurred before 5200 a B.P.,and the coastline tended to reach a stable state during 4500-800 a B.P..Following the Yellow River's entry into the sea in northern Jiangsu,the coastline in this region advanced rapidly since Song Dynasty,especially at the site of abandoned Yellow River Estuary.After the Yellow River's subsequent diversion in Qing Dynasty,the abandoned estuary experienced erosion and retreat,while the coastlines on both its northern and southern sides continued to advance seaward,resulting in the formation of the modern coastline.Approximately 7 000 years ago,the head of Yangtze River Estuary was located near Zhenjiang and the estuary exhibited a funnel shape.The Yangtze River Delta gradually formed through the emergence of river islands that expanded toward the southeast as it developed northward along the banks.The estuary narrowed over time,and the rate of development increased.The sediment from the Yangtze and Yellow Rivers has created significant deposition areas along the Yellow River Estuary,the Shandong Peninsula coast,northern Jiangsu,the Yangtze River Estuary,and the coasts of Zhejiang and Fujian.The Yangtze River Delta has the thickest sediment accumulation and its sediment center has been moving southeastward with the development of estuaries.The central Yellow Sea and the southwestern region of Cheju Island are characterized as low sedimentation areas.The land formation rates in the western Bohai Sea,northern Jiangsu,and the Yangtze River Delta were relatively large,whereas the Liaodong Bay and Hangzhou Bay experienced slower land formation rates.All five regions have exhibited a noticeable increase in the rate of land formation over the past 400 years.[Conclusions]This study compiled a database of paleocoastline and seabed sediment thickness in the western Bohai,Yellow and East China Seas and revealed the land formation processes since the past 7000 a B.P..The findings provide essential data support for research on sediment transport and paleoenvironment evolution in these regions.关键词
渤海/黄海/东海/海岸线演变/陆架沉积/全新世Key words
Bohai Sea/Yellow Sea/East China Sea/coastline evolution/continental shelf sedimentation/Holocene分类
海洋学引用本文复制引用
程鹏..渤、黄、东海7 000年以来海岸线和海底沉积物厚度的演变[J].厦门大学学报（自然科学版）,2025,64(3):446-460,15.基金项目
国家自然科学基金(42076008) （42076008）
