Grant-in-Aid for Overseas Scientific Survey.
|Research Institution||National Institute of Polar Research|
WATANABE Okutsugu National Institute of Polar Research (N. I. P. R), 研究系, 教授 (60111861)
NAKAZAWA Takakiyo Faculty of Science, Tohoku University
AOKI Shuji National Institute of Polar Research (N. I. P. R)
SATOW Kazuhide National Nagaoka College of Technology
IZUMI Kaoru Research Institute for Harzards in Snow Area, Niigata Univ.
KAWADA Kunio Faculty of Science, Toyama University
KAMIYAMA Koukichi Faculty of Science, Kyoto University
SHIJI Hitoshi Faculty of Science, Toyama University
NARITA Hideki Institute of Low Temperature Science Hokkaido University
FUJII Yoshiyuki National Institute of Polar Research (N. I. P. R)
NISHIO Fumihiko Hokkaido University of Education, Kushioro Campus
HAGEN J. O Norwigian Polar Research Institute
WOLD B Norwegian Water Resources and Energy Administration
THOMSEN H. H The Geological Survey of Greenland, Denmark Government
CLAUSEN H University of Cophenhagen, Geophysical Institute
KAWAMURA Kimitaka Faculty of Science, Tokyo Metropolitan University
WOLD B. ノルウェー水資源局, 主任
THOMSEN H.H. グリーンランド地調査所, 研究員
河村 公隆 東京都立大学, 理学部, 助教授 (70201449)
HAGEN J.O. ノルウェー極地研究所, 研究員
中沢 高清 東北大学, 理学部, 助教授 (30108451)
青木 周司 国立極地研, 研究系, 助手 (00183129)
佐藤 和秀 長岡工業高等専門学校, 助教授 (80113398)
和泉 薫 新潟大学積雪地域災害研究センター, 助教授 (50114997)
川田 邦夫 富山大学, 理学部, 助手 (20019003)
神山 孝吉 京都大学, 理学部付属地球物理学研究施設, 助手 (70135507)
成田 英器 北海道大学低温科学, 研究所, 講師 (20001662)
庄子 仁 富山大学, 理学部, 助教授 (50201562)
西尾 文彦 北海道教育大学, 釧路分校・教育学部, 教授 (40044789)
藤井 理行 国立極地研究所, 研究系, 助教授 (20125214)
|Project Fiscal Year
1989 – 1990
Completed(Fiscal Year 1990)
|Budget Amount *help
¥12,000,000 (Direct Cost : ¥12,000,000)
Fiscal Year 1990 : ¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1989 : ¥10,000,000 (Direct Cost : ¥10,000,000)
|Keywords||Arctic Region / Greenland Ice Sheet / Ice Core Analyses / Climatic Change / Environmental Change / Acid Rain / Little Ice Age / Volcanic Event Signal / 北極地域 / グリ-ンランド氷床 / 氷床コア解析 / 気候変動 / 環境変動 / 酸性雨 / 小氷期 / 火山活動シグナル|
Summary of Greenland Ice Core Investigations
Ice 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
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