著者

小泉 格 坂本 竜彦

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.119, no.3, pp.489-509, 2010-06-25 (Released:2010-08-30)

参考文献数

113

被引用文献数

7 8

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Annual sea-surface temperatures (SSTs) (°C) were derived from a regression analysis between the ratio of warm- and cold-water diatoms (Td' ratio) in 123 surface sediment samples around the Japanese Islands and measured mean annual SSTs (°C) at the core sites. The cross spectra between the atmospheric residual 14C (‰), and annual SSTs (°C) of cores DGC-6 (Japan Sea) and MD01-2421 (off Kashima), respectively, consist of five dominant periods: 6000, 2400, 1600, 950, and 700 years. The amplitude of fluctuations of annual SSTs (°C) in the millennial time scale during the Holocene after the Younger Dryas is within 6-10°C. Periodic variations of annual SSTs (°C) can be correlated within error to abrupt climatic events reported from different paleoclimatic proxy records in many regions of the Northern Hemisphere. The cooling time of annual SSTs (°C) also corresponds to the triple events of high 14C values in the atmospheric residual 14C records, as well as the Bond events in the North Atlantic.

著者

小泉 格

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.116, no.1, pp.62-78, 2007-02-25 (Released:2009-11-12)

参考文献数

69

被引用文献数

7 8

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The results of hydro-environment researches into marine and lacustrine sediments revealed climatic variations which seem to have some relationships between turns in world history and climatic changes. In the Japan Sea and northeast Pacific off Kashima from the Late Glacial to the Holocene, diatom temperature, Td' = (frequency of warm-water species) - (frequency of warm-and cold-water species) -1?100, values show rhythmic fluctuations with durations of 1 kyr and 400-500 yrs (Koizumi et al., 2004, 2006). This indicates a strong and regular inflow of the warm Tsushima Current into the Japan Sea as a branch of the warm Kuroshio Current. The decreases of Td' values correspond to a period of climatic deterioration under which cultural changes occurred in Japan. The paleoclimatic variations and the triple events of high 14C in the atmospheric residual 14C record denoted by Stuiver et al. (1991) are recognized in the diatom variations.A similar periodicity is also recognized in North Atlantic drift ice (Bond et al., 2001), concentrations of sea salt and terrestrial dust in the GISP2 ice core (O'Brien et al., 1995), in lake deposits from the Jura in France (Magny, 1995), Tibet (Gasse et al., 1991; Ji et al., 2005), and Alaska (Hu et al., 2003), and oxygen isotope variations from stalagmites in southern China (Wang et al., 2005) and Oman (Neff et al., 2001).Climatic deteriorations are synchronous with periods when serious changes occurred in human intellectual achievements during the Holocene. The Agricultural Revolution (11, 000-10, 000yr BC), with the cultivation of wild plants and domestication of wild animals to produce and secure food, seems to coincide with the Younger Dryas event. Increased agricultural production made it possible to afford a population not engaged in agriculture, for example, people engaged in handicrafts, festivals, and politics. This seems to occur in the period coinciding with T2 event in the T1-T4 triplets, which have Maunder-and Sporer-type patterns occurring in sets of three, denoted by Stuiver and Braziunas (1993). The religious courtesy belief in the recycling and the reinforcing of life was converted into a rational and systematic consideration of life based on universal theory. This conversion of thinking seems to coincide with the T3 event. Modern science was established in Europe in the 17th century. And now human beings are destroying natural environments using highly developed scientific technologies of their own. This is a negative revolution that human beings have never previously experienced.In the south-to-north transect of the cores from both the Pacific and Japan Sea sides of Honshu, Td' values indicate that the Kuroshio Current and Tsushima Warm Current are both weakening at present. The present interglacial period might end and become a cooler climatic condition like a Little Ice Age within 300 years. The insolation at 37°N among the Earth's orbital parameters is weak at present (Koizumi and Ikeda, 1997). However, the mean global temperature has risen about 0.5°C during the last century. Warming of the Earth, which is caused mainly by carbon dioxide in the atmosphere, has made natural environments unstable.

著者

伊東 俊太郎 安田 善憲 小泉 格 速水 融 埴原 和郎 梅原 猛

出版者

国際日本文化研究センター

雑誌

総合研究(B)

巻号頁・発行日

1990

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平成2年9月14日に平成3年度より出発する重点領域研究「地球環境の変動と文明の盛衰」(104 文明と環境)の第1回研究打合わせ会を京都市で実施した。出席者は研究代表者伊東俊太郎ほか13名。全体的な研究計画の打合わせと,今後の基本方針の確認ならびにニュ-スレタ-用の座談を実施した。平成2年12月1日,雑誌ニュ-トン12月号(教育社刊)誌上にて本重点領域研究にかかわる特集を組み,発表した。重点領域研究の広報活動の一環として研究計画の概要を朝日新聞11月6日付,毎日新聞1月3日付,日本経済新聞2月11日付に発表した。平成3年2月21日,ニュ-スレタ-「文明と環境」出発準備号を刊行し,関係者に配布した。内容は対談梅原猛・伊東俊太郎,座談安田喜憲ほか5名,特集,速水融ほかで31ペ-ジの構成である。大変好評で,日本経済新聞3月21日付にも紹介され,多くの研究者,企業関係者から問い合わせが殺到した。平成3年2月28日,第2回研究打合わせ連絡会を京都市で開催した。出席者は伊東俊太郎ほか重点領域計画研究関係者58名であった。午前中全体集会を実施し,午後分科会に分かれて,今後の研究方針について話し合った。今回の研究打合わせにより,58名もの参加者を得たことは,4月以降の本格的な出発に明かるい希望を抱かせた。平成3年3月8日,文部省にて重点領域研究審査会を実施し,公募研究の候補を選定した。

著者

小泉 格

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.91, pp.39-41, 2012

著者

小泉 格

出版者

Tokyo Geographical Society

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.116, no.1, pp.62-78, 2007-02-25

被引用文献数

3 8

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The results of hydro-environment researches into marine and lacustrine sediments revealed climatic variations which seem to have some relationships between turns in world history and climatic changes. In the Japan Sea and northeast Pacific off Kashima from the Late Glacial to the Holocene, diatom temperature, <I>Td</I>' = (frequency of warm-water species) - (frequency of warm-and cold-water species) <SUP>-1</SUP>?100, values show rhythmic fluctuations with durations of 1 kyr and 400-500 yrs (Koizumi et al., 2004, 2006). This indicates a strong and regular inflow of the warm Tsushima Current into the Japan Sea as a branch of the warm Kuroshio Current. The decreases of <I>Td</I>' values correspond to a period of climatic deterioration under which cultural changes occurred in Japan. The paleoclimatic variations and the triple events of high <SUP>14</SUP>C in the atmospheric residual <SUP>14</SUP>C record denoted by Stuiver <I>et al</I>. (1991) are recognized in the diatom variations.<BR>A similar periodicity is also recognized in North Atlantic drift ice (Bond <I>et al</I>., 2001), concentrations of sea salt and terrestrial dust in the GISP2 ice core (O'Brien <I>et al</I>., 1995), in lake deposits from the Jura in France (Magny, 1995), Tibet (Gasse et al., 1991; Ji <I>et al</I>., 2005), and Alaska (Hu <I>et al</I>., 2003), and oxygen isotope variations from stalagmites in southern China (Wang <I>et al</I>., 2005) and Oman (Neff <I>et al</I>., 2001).<BR>Climatic deteriorations are synchronous with periods when serious changes occurred in human intellectual achievements during the Holocene. The Agricultural Revolution (11, 000-10, 000yr BC), with the cultivation of wild plants and domestication of wild animals to produce and secure food, seems to coincide with the Younger Dryas event. Increased agricultural production made it possible to afford a population not engaged in agriculture, for example, people engaged in handicrafts, festivals, and politics. This seems to occur in the period coinciding with T<SUB>2</SUB> event in the T<SUB>1</SUB>-T<SUB>4</SUB> triplets, which have Maunder-and Sporer-type patterns occurring in sets of three, denoted by Stuiver and Braziunas (1993). The religious courtesy belief in the recycling and the reinforcing of life was converted into a rational and systematic consideration of life based on universal theory. This conversion of thinking seems to coincide with the T<SUB>3</SUB> event. Modern science was established in Europe in the 17th century. And now human beings are destroying natural environments using highly developed scientific technologies of their own. This is a negative revolution that human beings have never previously experienced.<BR>In the south-to-north transect of the cores from both the Pacific and Japan Sea sides of Honshu, <I>Td</I>' values indicate that the Kuroshio Current and Tsushima Warm Current are both weakening at present. The present interglacial period might end and become a cooler climatic condition like a Little Ice Age within 300 years. The insolation at 37°N among the Earth's orbital parameters is weak at present (Koizumi and Ikeda, 1997). However, the mean global temperature has risen about 0.5°C during the last century. Warming of the Earth, which is caused mainly by carbon dioxide in the atmosphere, has made natural environments unstable.

著者

小泉 格

出版者

一般社団法人 日本地質学会

雑誌

地質学雑誌 (ISSN:00167630)

巻号頁・発行日

vol.115, no.7, pp.311-324, 2009 (Released:2009-12-08)

参考文献数

34

被引用文献数

1

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(1)古海洋学は,海洋システムの発達と変動を研究する学問分野である.古海洋研究の進め方と古海洋研究の課題を記述した.微化石の研究は,層序,古環境,古気候など地質学に関わって貢献してきた.この努力を生物学の分野で行えば,微化石による進化古生物学を確立できる.(2)第四紀の開始時期の問題,氷期-間氷期の10万年サイクルの開始時期とその原因,氷期から間氷期への急激な温暖化(ターミネーション)の問題,および最終間氷期の始まりであるターミネーションIIについて研究の現状をまとめた.(3)15万年前以降における珪藻化石群集の周期的変動が,三陸沖6本と日本海2本のピストンコア堆積物で認められた.三陸沖コアに見られる環境変動は,北半球における環境変動とほぼ同一の周期値を持つことが判明した.