Sedimentary record of climate change in a high latitude fjord—Kongsfjord  

作　　者：Hang Wu Binbin Deng Jinlong Wang Sheng Zeng Juan Du Peng Yu Qianqian Bi Jinzhou Du 

机构地区：[1]State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai,200241,China [2]Monitoring Center of Aquatic Environment of Pearl River Basin,Guangzhou,510611,China [3]Research Centre for Eco-Environmental Engineering,Dongguan University of Technology,Dongguan,523808,China [4]Big Data Institute of Digital Natural Disaster Monitoring in Fujian,Xiamen University of Technology,Xiamen,361024,China

出　　处：《Acta Oceanologica Sinica》2023年第1期91-102,共12页海洋学报（英文版）

基　　金：The National Natural Science Foundation of China under contract Nos 42107251 and 41706089;the Natural Science Foundation of Fujian Province under contract No.2020J05232.

摘　　要：The sedimentary record of climate change in the Arctic region is useful for understanding global warming.Kongsfjord is located in the subpolar region of the Arctic and is a suitable site for studying climate change.Glacier retreat is occurring in this region due to climate change,leading to an increase in meltwater outflow with a high debris content.In August 2017,we collected a sediment Core Z3 from the central fjord near the Yellow River Station.Then,we used the widely used chronology method of 210Pb,^(137)Cs,and other parameters to reflect the climate change record in the sedimentary environment of Kongsfjord.The results showed that after the mid-late 1990s,the mass accumulation rate of this core increased from 0.10 g/(cm^(2)·a)to 0.34 g/(cm^(2)·a),while the flux of^(210)Pb_(ex)increased from 125 Bq/(m^(2)·a)to 316 Bq/(m^(2)·a).The higher sedimentary inventory of^(210)Pb_(ex)in Kongsfjord compared to global fallout might have been caused by sediment focusing,boundary scavenging,and riverine input.Similarities between the inventory of^(137)Cs and global fallout indicated that terrestrial particulate matter was the main source of^(137)Cs in fjord sediments.The sedimentation rate increased after 1997,possibly due to the increased influx of glacial meltwater containing debris.In addition,the^(137)Cs activity,percentage of organic carbon(OC),and OC/total nitrogen concentration ratio showed increasing trends toward the top of the core since 1997,corresponding to a decrease in the mass balance of glaciers in the region.The results ofδ^(13)C,δ^(15)N and OC/TN concentration ratio showed both terrestrial and marine sources contributed to the organic matter in Core Z3.The relative contribution of terrestrial organic matter which was calculated by a two-endmember model showed an increased trend since mid-1990s.All these data indicate that global climate change has a significant impact on Arctic glaciers.

关 键 词：Kongsfjord RADIONUCLIDE organic carbon/total nitrogen(OC/TN)concentration ratio δ^(13)C δ^(15)N sediment record climate change 

分 类 号：P467[天文地球—大气科学及气象学] P512.2