Terrestrial input changes and their controlling factors as revealed by the elemental geochemical evidence in the East China Sea muddy area during the last century
{"title":"Terrestrial input changes and their controlling factors as revealed by the elemental geochemical evidence in the East China Sea muddy area during the last century","authors":"","doi":"10.1016/j.catena.2024.108317","DOIUrl":null,"url":null,"abstract":"<div><p>Terrestrial input changes in large river-dominated marginal seas are influenced by anthropogenic and climate forces with spatiotemporal heterogeneity that has not been well clarified. In this work, based on elemental geochemical evidence of a centennial-scale sediment core from the muddy belt in the East China Sea (ECS), together with previously published organic geochemical data of the same core and selected environmental parameters, we reveal a synchronous decline in terrestrial input with enhanced anthropogenic activities after <em>ca</em>. 2000. The rapid decrease in 2000–2004 may be attributed to the construction of dams such as the Three Gorges Dam (TGD). During the pre-TGD period, the terrestrial input maintained stable high values (except for a distinct peak in 1965), which coincided with enhanced chemical weathering, stable annual temperature, increased precipitation, and strong East Asian winter monsoon (EAWM) driven by climatic factors. After <em>ca</em>. 2000, anthropogenic activities gradually became the dominant controlling factor on terrestrial input variations. In addition, significant coastal erosion recorded by Al/Si ratios during 2000–2004 and intensified nearshore eutrophication captured by δ<sup>15</sup>N values from 1950 to 1985 are linked to the construction of the TGD and increased fertilizer usage, respectively. Overall, our findings provide vital insights into modern processes using inorganic and organic geochemical proxies in marginal seas. Notably, terrestrial input and related geochemical parameters in representative cores from north to south in this region show considerable spatiotemporal variations, requiring further investigation into their underlying causes.</p></div>","PeriodicalId":9801,"journal":{"name":"Catena","volume":null,"pages":null},"PeriodicalIF":5.4000,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catena","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0341816224005149","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Terrestrial input changes in large river-dominated marginal seas are influenced by anthropogenic and climate forces with spatiotemporal heterogeneity that has not been well clarified. In this work, based on elemental geochemical evidence of a centennial-scale sediment core from the muddy belt in the East China Sea (ECS), together with previously published organic geochemical data of the same core and selected environmental parameters, we reveal a synchronous decline in terrestrial input with enhanced anthropogenic activities after ca. 2000. The rapid decrease in 2000–2004 may be attributed to the construction of dams such as the Three Gorges Dam (TGD). During the pre-TGD period, the terrestrial input maintained stable high values (except for a distinct peak in 1965), which coincided with enhanced chemical weathering, stable annual temperature, increased precipitation, and strong East Asian winter monsoon (EAWM) driven by climatic factors. After ca. 2000, anthropogenic activities gradually became the dominant controlling factor on terrestrial input variations. In addition, significant coastal erosion recorded by Al/Si ratios during 2000–2004 and intensified nearshore eutrophication captured by δ15N values from 1950 to 1985 are linked to the construction of the TGD and increased fertilizer usage, respectively. Overall, our findings provide vital insights into modern processes using inorganic and organic geochemical proxies in marginal seas. Notably, terrestrial input and related geochemical parameters in representative cores from north to south in this region show considerable spatiotemporal variations, requiring further investigation into their underlying causes.
期刊介绍:
Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment.
Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.