Ice Core Study on Palaeoclimate in the Arctic Region

北极地区古气候的冰芯研究

基本信息

批准号：
01041101
负责人：
WATANABE Okutsugu
金额：
$ 7.68万
依托单位：
National Institute of Polar Research
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01041101/
关键词：
Arctic Region Greenland Ice Sheet Ice Core Analyses Climatic Change Environmental Change Acid Rain Little Ice Age Volcanic Event Signal

项目摘要

Summary of Greenland Ice Core InvestigationsIce cores from polar glaciers and ice sheets provide the means to study the climatic and environmental changes in the past by conducting physical and chemical stratigraphic anlyses on the cores. A team member of the Japanese Arctic Research Expedition (JAGE) successfully obtained one 101m-long and one 205m-long ice cores at Site J (65^ﾟ 51.9' N, 46^ﾟ 15.9' w), Greenland during the field activities in May-July, 1989. The field observations on the cores included visual stratigraphy (continuous) and ECM measurements (continuous), and pH and EC examinations (discrete). Cores after processing in the field were transported to Japan for detailed, multi-parameter laboratory investigations. The results hitherto obtained on cores are summarized as follows.Chronology : Accumulation rate at Site J was studied by conducting measurements on visual stratigraphy, delta^<18>O, tritium and ^<210>Pb analyses. ECM profile obtained shows well-defined peaks at dep … More ths of 86.9 and 102.8m, which are associated with the known volcanic events in 1815 (Tambora) and 1783 (Laki) respectively. These findings suggest that an average accumulation rate at Site J for the period from 1783 to 1988 AD is 0.39m/a and the age of ice at the bottom of the 205m-long core is 435 a B. P.Temperature : Melt feature percentages (MFP) of the cores were analysed to extract information on the near surface temperature record in the past. The depth variations of MFP profile generally correlate well with delta^<18>O changes. Two minima observed in MFP profile at depths of 78 and 150m, corresponding to around 1840 and 1690 AD respectively, may reflect an occurrence of a colder period known as Little Ice Age.Chemistry : The major ion concentrations such as SO_4, NO_3, Na, Cl and K were measured on selected samples. The anthropogenic SO_4 and NO_3 inputs to Greenland are clearly demonstrated after the industrial revolution and rapidly increased in the 20-th century as also shown in the profile. Organic chemistry analysis has been made on various species including particulate organic carbon, hydrocarbon and carboxylic acid. A siginificant increase in anthropogenic hydrocarbon concentration (unresolved complex mixture) is observed in the 20-th century.An international workshop was held to discuss and cross-correlate the various study results, and summarize the present status of knowledge for future research directions. An emphasis was made on the necessity to conduct shallow-core network analyses for a betterunderstanding of the environmental characteristics in Arctic region. Less

格陵兰冰芯调查摘要日本北极研究考察队（JAGE）的一名团队成员成功地对冰芯进行了物理和化学地层分析，为研究过去的气候和环境变化提供了手段。在J地点（北纬65^ﾟ 51.9'，46^ﾟ）获得1个101m长和1个205m长的冰芯15.9' w），格陵兰岛，1989 年 5 月至 7 月进行实地活动期间。对岩心的实地观察包括目视地层学（连续）和 ECM 测量（连续）以及岩心处理后的 pH 和 EC 检查（离散）。现场被运送到日本进行详细的多参数实验室调查，迄今为止在岩心上获得的结果总结如下。年代：通过进行研究来研究 J 地点的堆积率。目视地层学测量、δ^<18>O、氚和^<210>Pb 分析显示出深度为 86.9 和 102.8m 的明确峰值，这与 1815 年已知的火山事件有关。 (Tambora) 和 1783 (Laki) 这些发现表明 J 点自 1783 年以来的平均堆积率。到公元 1988 年为 0.39m/a，205m 长核心底部的冰龄为 435 a B。 P.温度：分析了核心的融化特征百分比 (MFP)，以提取有关近地表温度记录的信息。 MFP剖面的深度变化通常与在78和18°深度处的MFP剖面中观察到的两个最小值相关。 150m，分别对应于公元1840年和1690年左右，可能反映了被称为小冰期的较冷时期的发生。化学：在选定的样品上测量了SO_4、NO_3、Na、Cl和K等主要离子浓度。工业革命后，格陵兰岛的 NO_3 输入量明显增加，并在 20 世纪迅速增加，对各种物种的有机化学分析也显示了这一点。 20 世纪观察到人为碳氢化合物浓度（未溶解的复杂混合物）显着增加，包括颗粒有机碳、碳氢化合物和羧酸。举办了一次国际研讨会，讨论和交叉关联各种研究结果，并总结强调了进行浅层核心网络分析的必要性，以更好地了解北极地区的环境特征。