出版者
横浜経済学会
雑誌
エコノミア (ISSN:00129712)
巻号頁・発行日
vol.67, no.1・2, pp.71-78, 2017-03
著者
逆井 聡人
出版者
東京大学大学院総合文化研究科言語情報科学専攻
雑誌
言語情報科学 (ISSN:13478931)
巻号頁・発行日
vol.13, pp.85-102, 2015-03-01

本稿は、アジア太平洋戦争直後の東京における戦災復興を考察する。本稿が対象とするのは、都市計画そのものや政府の政策等ではなく、戦災復興期の東京を描いた二本の映画である。一つは『20 年後の東京』という東京都都市計画課が作成したPR 映画であり、もう一つは黒澤明が監督した『野良犬』である。東京の戦災復興計画を宣伝する『20 年後の東京』がその計画の思想を伝える際に用いるレトリックを分析し、その背後にある植民地都市経営の経験とそれを「民主的」という言葉で覆い隠し、計画の正当性を偽装する態度を読み取る。また計画の障害として語られる闇市を取り上げ、その復興期における役割を評価した上で映画の言説との齟齬を明らかにする。そして、その闇市を映画の主要な空間として取り込んだ『野良犬』が、その空間にいかなる役割を担わせているかを主人公の復員兵・村上を通して考察する。本稿は都市を語る上で帝国主義の過去を忘却しようとする言説に対して、抗う拠点としての闇市という空間を位置付けることを目的とする。
著者
宮原 ひろ子 Miyahara Hiroko 毛受 弘彰 Menjo Hiroaki 桑名 宏輔 Kuwana Kousuke 増田 公明 Masuda Kimiaki 村木 綏 Muraki Yasushi 中村 俊夫 Nakamura Toshio
出版者
名古屋大学年代測定資料研究センター
雑誌
名古屋大学加速器質量分析計業績報告書
巻号頁・発行日
vol.16, pp.57-64, 2005-03

This paper presents the variation of solar activity during the Maunder Minimum (1645-1715 AD) deducted from radiocarbon content in tree-rings. Radiocarbon is produced by the galactic cosmic rays, which are modulated by the solar wind and the interplanetary magnetic field in the heliosphere. The production rate of radiocarbon, therefore, reflects the state of solar magnetic activity. Most distinct index of solar magnetic activity it the group sunspot number. The variations of sunspot number have shown clear cyclicity since the 18^<th> century with average length being about eleven years. The sunspots, however, have once almost disappeared during the period of 1645-1715 AD due to extraordinary weakening of solar activity. This period has been called as the Maunder Minimum. There is no remarkable cyclicity in the sunspot variations. We, therefore, investigated the cyclicity of radiocarbon content in tree rings from the Maunder Minimum in order to clarify the characteristics of solar activity during this period. We compared two radiocarbon records obtained newly by our group and by Stuiver et al. The results of frequency analyses have shown that solar magnetic reversals had maintained through the Maunder Minimum and that the length of the "eleven-year" cycle was stretched to 13-15 years.
著者
早川 由紀夫
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.60, no.4, pp.507-592, 1986-03-31

The eruptive activity of Towada Volcano is documented by the tephrostratigraphic study. More than 20 eruptive episodes are described in detail with isopach maps and isograde maps of maximum pumice size, maximum lithic size, and median diameter for the individual fallout deposits. The activity of the volcano started about 200,000 years ago along the NE-SW trending line crossing the present lake Towadako and relatively small-scale volcanoes were formed. A caldera 11km×11km wide was formed as a result of several eruptive episodes during the period about 55,000 to 13,000 years ago, three of which included voluminous pyroclastic flow eruptions. The post-caldera activity occured at a rate of one eruptive episode every 1,000 to 2,000 years and a stratovolcano and two lava domes were formed in the caldera. The latest eruptive episode was dated 1,250 y B. P. by the radiocarbon method. Rocks of Towada Volcano cover a wide range from basaltic andesite to rhyodacite (SiO2 : 51-70wt.%) with phenocrysts of plagioclase, augite, hypersthene, and magnetite with occasional olivine. Horn-blende is characteristically found in the pyroclastic deposits of 13,000 years old and in some earlier deposits. Volumes, V, of two plinian deposits are determined by the crystal method : 6.7km3 for the Chuseri deposit and 2.2km3 for the Nambu deposit. Then an empirical formula, V=12.2 TS, is obtained for the practical volume estimation, where T is the thickness of an isopach and S is the area enclosed by the isopach. Application of the formula to the fallout deposits of Towada Volcano suggests that the total magma erupted during the past 55,000 years amounts to 1.5×1017g. This corresponds to the discharge rate of dense rock equivalent to 1.1km3 per thousand years. The cross-wind range, Rc, of the pyroclasts of a given size may be a good indicator of the maximum height reached by the pyroclasts in the eruption column. It is found that the Rc is relatively large for those deposits whose erupted masses are relatively large. The dispersal of a fallout deposit is also seriously affected by winds. A plausible solution of the eruption condition for the Nambu deposit is that 4mm size lithic fragments reached the maximum height of 15km in the eruption column, then they were detached from the column and displaced by winds having an average velocity of 30m/s. After a 20 min flight, they fell upon the ground 48km east of the source. Whole-deposit grain size populations are determined for the Chuseri and Nambu plinian deposits. The Chuseri population is similar to the New Zealand examples. However, the Nambu population is distinctly coarser than the others.