基于^(210)Pb测年法的楚科奇海陆架北缘有机碳沉积通量研究  

^(210)Pb-DERIVED ORGANIC CARBON DEPOSITION FLUX ON THE NORTH CHUKCHI SHELF

作　　者：余雯[1,2] 何建华[1,2] 李奕良[1,2] 苏健[1,3] 

机构地区：[1]国家海洋局海洋-大气化学与全球变化重点实验室,福建厦门361005 [2]国家海洋局第三海洋研究所,福建厦门361005 [3]清华大学工程物理系,北京100084

出　　处：《极地研究》2012年第4期391-396,共6页Chinese Journal of Polar Research

基　　金：中国极地科学战略研究基金(20100212);国际极地年中国行动计划专项(IPY2008-P050400104-03)资助

摘　　要：有机碳沉积作用在一定时间尺度上形成海洋碳汇作用的最终净效应,北冰洋陆架的有机碳沉积作用在全球碳循环中有着尤为重要的地位。为了测定楚科奇海陆架的有机碳沉积通量,应用210Pb测年法对中国第3次北极考察R17站位的沉积物样品的年龄及沉积速率进行了分析测定,并结合表层沉积物中有机碳的含量计算得到了楚科奇海陆架北缘的有机碳沉积通量。结果显示,该站位的沉积速率为0.6 mm.a-1,表观沉积质量通量为0.72 kg.m-2.a-1,有机碳沉积通量为517 mmol C.m-2.a-1。经估算,真光层输出的有机碳中约有29%被长期封存在沉积物中,远高于中低纬度的正常值(～10%),说明楚科奇海陆架区具有高效的碳汇作用。Deposition of organic carbon forms the final net effect of the ocean carbon sink at a certain time scale. The or- ganic carbon deposition on the Arctic shelf plays a particularly important role in the global carbon cycle because of the broad shelf area. To determine the organic carbon deposition flux at the northern margin of the Chukchi Shelf, the 21~Pb dating method was used to analyze the age and deposition rate of sediment samples from station R17 of the 3rd Chinese National Arctic Research Expedition. The results showed that the deposition rate was 0.6 mm · a-t, the apparent deposition mass flux was 0.72 kg · m-2 . a-1, and the organic carbon deposition flux was 517 mmol C· m-2 . a-1. It was estimated that 29% of the export organic carbon flux out of the euphotic zone was transferred and chronically buried into the sediment, a value that was much higher than the average ratio （ - 10% ） for the low-to mid-latitude region, indicating a highly effective carbon sink at the northern margin of the Chukchi Shelf.

关 键 词：有机碳沉积通量 210Pb测年法楚科奇海陆架 

分 类 号：P736.21[天文地球—海洋地质]