著者
楠本 成寿 福田 洋一 竹村 恵二 竹本 修三
出版者
学術雑誌目次速報データベース由来
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.110, no.1, pp.32-43, 2001
参考文献数
35
被引用文献数
1 11

In order to solve a mechanical inconsistency that the Osaka Bay basin exists between the Median Tectonic Line (MTL) and Arima-Takatsuki Tectonic Line (ATTL) (right-lateral left-stepping faults), we attempted to investigate and evaluate the basin forming mechanism at the termination of right-lateral left-stepping faults by means of the dislocation modeling.<BR>The results of the numerical simulations show that the sedimentary basin can be formed at the termination of the right-lateral left-stepping faults develop, if the secondary fault caused by the rightlateral motion is a reverse fault and its displacement is larger than 20% of the lateral motion. We applied this model to the fault distribution in the Kinki district, and found that tectonic structures around the Osaka Bay can be explained by combination of 1) the right-lateral motion of the MTL and ATTL and 2) the reverse motion of their secondary faults, <I>i.e</I>., Nara-Toh'en Fault, Ikoma Fault and Rokko-Awaji Fault Systems.
著者
田切 美智雄 森本 麻希 望月 涼子 横須賀 歩 DUNKLEY Daniel J. 足立 達朗
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.119, no.2, pp.245-256, 2010-04-25
参考文献数
29
被引用文献数
8 20

Hitachi metamorphic rocks located in the southern part of the Abukuma Mountains, Northeast Japan, distinctively contain meta-volcanic rocks and meta/sheared granitoids. The igneous ages of meta-granite and meta-porphyry from the Hitachi metamorphic rocks were determined by the SHRIMP zircon method. In this paper, we describe occurrence, petrography, and petrochemical characteristics of these studied rocks. Meta-porphyry, with an igneous age of 506 Ma, intrudes into the meta-volcanic rocks of the Akazawa Formation of the Hitachi metamorphic rocks and has a micrographic texture and a spherulitic texture of an igneous origin. Previous studies have already reported an igneous age of 491 Ma for meta/sheared granitoids using the SHRIMP zircon method. Cambrian meta/sheared granitoid samples occur widely as a granitic body in the northeastern part of the Hitachi metamorphic rocks. (A) Meta-granite of the same age (498 Ma) as the sample used for the above dating is found as boulders in meta-conglomerates. The meta-conglomerate, which is found in the Daioin Formation of the Hitachi metamorphic rocks, lies unconformably on a Cambrian meta-granite body. Both meta-volcanic rocks and meta/sheared granitoids have chemical characteristics commonly associated with island arc volcanism. As such, the Akazawa Formation is likely to have originated in the Cambrian era, although we have no SHRIMP age for meta-volcanic rocks of the Akazawa Formation.
著者
齋藤 有 田村 亨 増田 富士雄
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.114, no.5, pp.687-704, 2005-12-25
被引用文献数
3 12

Hyperpycnal flow is one type of turbidity current, which is generated at a river mouth when the suspended sediment concentration of river discharge is so high that the density of the effluent exceeds the water of the receiving basin. Generations of this type of flow have become a common phenomenon recently. A lot of hyperpycnal flow deposits are expected to be preserved naturally in stratigraphic records. Hyperpycnal flow deposits (hyperpycnites) might become an innovative factor for turbidite paradigm considering the particularity of the flow, and bring facies analysis towards the next step. In this review paper, the criteria for identifying hyperpycnal flow deposits from strata are proposed by summarizing studies on hyperpycnal flow and its deposits. Typical characteristics of hyperpycnal flow include : (1) vertical succession composed of 2 parts, inversely-graded lower part and normally-graded upper part, (2) internal scour surface, (3) repetitive alternation of fine-grained and coarse-grained layers, or laminated and massive layers, (4) abrupt pinch-out of beds, and (5) inclusion of terrestrial materials such as leaves. Hyperpycnal flow gradually waxes and then wanes to terminate in response to flood conditions, resulting in (1). The internal scour surface (2) developed in accordance with the degree of waxing. Fluctuations of flow velocity and sediment concentration due to changes of river discharge and/or internal waves can occur during the flow event, and lead to repetitive alternation of (3). Because of the fresh interstitial water, the marine hyperpycnal flow might start to lift off after losing suspended sediments to the degree that the density of the flow is exceeded by ambient saline water. This results in (4) at the lifting point. Terrestrial materials referred to in (5) are the result of the fact that the hyperpycnal flow originated from terrestrial floods.<BR>A much wider variety of deposits, which form in one history of a turbidity current, than that expected from the Bouma sequence model, is shown. Exploration of the variety has just started.
著者
矢野 桂司 中谷 友樹 磯田 弦 高瀬 裕 河角 龍典 松岡 恵悟 瀬戸 寿一 河原 大 塚本 章宏 井上 学 桐村 喬
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.117, no.2, pp.464-478, 2008-04-25
被引用文献数
2 19

バーチャル京都は,歴史都市京都の過去,現在,未来を探求することを目的に,コンピュータ上に構築されたバーチャル時・空間である。本研究では,最先端のGISとVR技術を用いて,複数の時間スライスの3次元GISからなる4次元GISとしてのバーチャル京都を構築する。本研究は,まず,現在の京都の都市景観を構築し,過去にさかのぼる形で,昭和期,明治・大正期,江戸期,そして,京都に都ができた平安期までの都市景観を復原する。<br> バーチャル京都を構築するためには以下のようなプロジェクトが行われた。a)京都にかかわる,現在のデジタル地図,旧版地形図,地籍図,空中写真,絵図,景観写真,絵画,考古学資料,歴史資料など位置参照可能な史・資料のGIS データの作成,b)京町家,近代建築,文化遺産を含む社寺など,現存するすべての建築物のデータベースおよびGISデータの作成,c)上記建築物の3次元VRモデルの構築,d)上記GISデータを用いた対象期間を通しての土地利用や都市景観の復原やシミュレーション。<br> バーチャル京都は,京都に関連する様々なデジタル・アーカイブされたデータを配置したり,京都の繊細で洗練された文化・芸術を世界に発信したりするためのインフラストラクチャーである。そして,Webでのバーチャル京都は,歴史的な景観をもつ京都の地理学的文脈の中で,文化・芸術の歴史的データを探求するためのインターフェイスを提供する。さらに,バーチャル京都は,京都の景観計画を支援し,インターネットを介して世界に向けての京都の豊富な情報を配信するといった重要な役割を担うことになる。
著者
新井 智一
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.120, no.4, pp.676-691, 2011-08-25
被引用文献数
2

This paper discusses locational conflicts surrounding a new waste disposal facility in Koganei City from the viewpoint of "the politics of scale". Since 1957, Koganei, Chofu, and Fuchu cities have disposed of their waste at Nimaibashi Waste Disposal Facility. In 2007, Koganei City officials proposed the construction of a new facility by 2017 at the site of the Nimaibashi Waste Disposal Facility, which was located at the periphery of Koganei City, or at the site of a former Janome sewing machine factory, which was located at the center of the city. Although people residing near both sites protested against the construction of the new facility, the Koganei City officials decided to construct the new facility at the site of the Nimaibashi Waste Disposal Facility. The reason for this decision is summarized as follows: (1) Most of the citizens of Koganei City appeared to be indifferent to this locational conflict; (2) The Koganei City officials were adamant about constructing an incineration facility; (3) The actions of the people residing near the former Janome sewing factory, unlike those of the people residing near Nimaibashi Waste Disposal Facility, were successful in protesting given the scale of Koganei City.
著者
若林 芳樹 伊藤 悟
出版者
東京地学協会 = Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.103, no.3, pp.221-232, 1994-06-25
参考文献数
34
被引用文献数
4 6

Geographical approach to cognitive maps has mainly focused on measurement of their spatial patterns. Recently Lloyd (1989) devised a useful method for analyzing the components of distortions in cognitive maps by means of Euclidean regression. Until now, however, this method has not yet been validated. The purpose of this study was to reexamine his concepts about the distortions in cognitive maps and to test their validity.We pointed out several discrepancies between the concepts of distortions and their operational definitions given by Lloyd (1989). To overcome this problem, the absolute distortion that appears in the configuration before Euclidean regression ought to be distinguished from the systematic distortion that is measured by the parameters of Euclidean regression. While the systematic distortion that indicates a Euclidean property of the distortion can be explained by alignment and rotation heuristics (Tversky, 1981) and implicit scaling model (Holyoak and Mah, 1982), the relative distortion that remains after Euclidean regression cannot be explained by general theories. In addition, these geometrical components of distortion ought to be distinguished from statistical ones, namely, distortion (central tendency) and fuzziness (dispersion) defined by Gale (1982).On the basis of this conceptualization, we carried out an empirical analysis of the distortion in the cognitive map of Kanazawa City. The data used in this study were obtained by a conditional sketch mapping drawn from 113 students of Kanazawa University. Locations to be answered were 21 transportation nodes within the central part of the city known by more than 90 percent of the students. From these locations, two major landmarks of CBD were selected as reference points. Subjects were asked to indicate the remaining 19 locations on the legal-size sheet in which the two reference points were printed.We detected the absolute distortions, overlaying the cognitive maps for all samples on the actual map so as to fit the locations of two reference points into the actual ones. The patterns of the absolute distortion indicated that the amount of errors increased with distance from the reference points, and that the locations in cognitive maps commonly shifted outward from the actual ones. Specifically, these displaced locations in southern or eastern part of the city indicated a counterclockwise shift, which suggested a directional bias in cognitive maps.In order to separate the systematic distortion from the relative one, each of the cognitive configurations was fitted into the actual map by Euclidean regression. Parameter estimates of the scale change averaged 0.593, which suggested that cognitive maps were enlarged about twice the size of the actual map. Mean direction of the rotated angle amounted to-22.2 degrees, which implied that cognitive maps were rotated counterclockwise about 20 degrees from the actual map so as to coordinate the cardinal directions of the cognitive map with the actual one. This tendency can be due to the displacement of two river channels as major reference lines in Kanazawa from cardinal directions.After eliminating the systematic distortions by Euclidean regression, the actual map was overlaid with all the cognitive maps. The overlaid maps indicated that the local patterns of relative distortions reflected hierarchical structure of cognitive maps (Stevens and Coupe, 1978) although the amount of them was smaller than that of the systematic distortions.
著者
田中 和広 石原 朋和
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.118, no.3, pp.499-510, 2009-07-07
被引用文献数
5 10

The Nabetachiyama Tunnel 9116 m long was excavated in Tokamachi City, Niigata Prefecture and encountered the serious difficulties during excavation. In particular, a 600 m long section in the Matsudai area had experienced difficulties caused by swelling mudstone in the Tertiary Sugawa Formation. A 120 m bore hole long was excavated in the neighborhood of the section and geological and geochemical examinations of sampled cores were carried out to investigate the formation mechanism of the swelling rock mass. Mudstone distributed deeper than 50 m in the bore hole can be correlated to the tunnel troubled section geologically and geochemically. The section is assumed to be composed of mud breccia with mudstone fragments and clayey matrix, which is thought to be generated by hydro-fracturing of mudstone, showing weak strength due to large quantities of clay minerals. A gas pressure of 1.6 MPa thought to be caused by degassing of methane was measured during tunnel construction, which would increase the swelling properties. Mud breccia distributed deeper than 50 m contains a lot of Na-smectite formed in highly saline pore water ascending from deep underground. The result of slaking test showed that mud breccia filled with saline groundwater is characterized by quick slaking and swelling due to the marked contraction of Na-smectite when drying. In summary, the swelling rock mass distributed in the troubled section was formed by the weak rock strength caused by hydro-fracturing and high gaseous pressure generated by degassing. Furthermore, quick slaking caused by repeated wetting and drying was another reason for swelling during excavation.
著者
大和 広明 三上 岳彦 高橋 日出男
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.120, no.2, pp.325-340, 2011-04-25
参考文献数
12
被引用文献数
3 18

We analyze the influence of sea breeze on temperature distribution in the Kanto Plain (central Japan) on a day that a sea breeze front was detected (known as sea-breeze front days) using high-resolution temperature data observed by our research team.<br> The high-temperature area on sea breeze front days moves northwest from central Tokyo, and was located at Kawagoe city (middle Kanto Plain) at 14 JST, and the northern Kanto Plain at 16 to 18 JST, respectively. This high-temperature area appears at the head of the sea breeze front to the leeward of central Tokyo, where the daily maximum temperature is highest in Kawagoe city and the northern Kanto Plain. After the sea breeze front passes, the area where the temperature is higher than that at the circumference is distributed in the shape of a wedge. This wedge-shaped area is located to the leeward of central Tokyo where the wind from Tokyo Bay and Sagami Bay forms a convergence zone. The high-temperature area around Kawagoe city, which cannot be found on days with strong winds, is formed from the hindrance of cold air advection caused by sea breeze front penetration.<br> On the other hand, high temperatures in the northern Kanto Plain may not be related to the penetration of sea breeze fronts, which do not reach the northern Kanto Plain on days when the daily maximum temperature is recorded. However, the temperature in the northern Kanto Plain is higher on sea breeze days than on strong southerly wind days, and this suggests that local circulation plays an important role in causing high temperatures in the northern Kanto.
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

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
柳井 修一 青木 一勝 赤堀 良光
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.119, no.6, pp.1079-1124, 2010-12-25
被引用文献数
8 64

Median Tectonic Line (MTL) and Fossa Magna (Itoigawa-Shizuoka Tectonic Line) had long been considered to be the most critical fault boundaries controlling development of the Japanese Islands since Naumann (1885) and Kobayashi (1941). After the appearance of plate tectonics, several new interpretations emerged, <i>e.g.</i>, sub-surface Benioff plane for the MTL. In this paper, we propose that those tectonic lines, major faults, and Tanakura Tectonic Line (TTL) were formed through a process at micro-plate boundaries during the opening of the Japan Sea in the Miocene.<br> MTL could have been formed along the consuming boundary between the PHS plate and Japan Sea microplate, which has shifted southward to the Nankai trough, accompanying large-scale tectonic erosion. Fossa Magna was formed as a gigantic transform fault with a transtension component in the Medial-Japan Sea when opening was initiated. The eastern and western boundaries of the Japan Sea must be a strike-slip fault, corresponding to TTL to the east, and a newly proposed strike-slip fault called the West Kyushu Tectonic Line, respectively. Fossa Magna, a medial region defined by two NS-trending Miocene parallel faults in central Honshu, defined by Nauman (1885) could be interpreted to be the largest transform fault in the Medial-Japan Sea to offset the spreading axis when the Japan Sea opened.<br> It should be emphasized that large-scale tectonic erosion occurred in front of consuming plate boundaries facing the PHS and PAC plates oceanward during the opening of the Japan Sea. The volume of tectonic erosion is calculated to be 17,581,500 km<sup>3</sup>, which is equivalent to 2/3 of the present-day Japan arc crust, which is sufficient to reach the depth of the megalith between the upper and lower mantle boundary, even with 10 km thickness of materials eroded and transported along the Benioff zone.<br> Although MTL, Fossa Magna, and TTL are remarkable in the geology of Japan, these young faults never affected the orogeneses of Japan back to 520 Ma, which grew the continental crust of Japan. We propose that microplate boundary processes decreased the volume of the Japan crust.
著者
遠藤 匡俊
出版者
社団法人 東京地学協会
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.113, no.3, pp.421-424, 2004-01-01

蝦夷地は2度にわたり幕府の直轄地となり,アイヌの風俗・習慣を和人風に変えるという同化政策が実施された。この同化政策によって,アイヌの個人名がアイヌ名(アイヌ語の名)から和名(日本語の名)に改名される和名化が生じた。これまで和名化は,幕府の同化政策によってアイヌ文化が変容する事例として注目されてきた。また,アイヌ社会には「近所に生きている人と同じ名をつけない」という個人名の命名規則が存在していた。個人名の命名にあたって,文字をもたなかったアイヌは,周囲の人々の名を思い浮かべて,同じ名とはならないように配慮したものと考えられる。しかし,従来の研究では,和名化の展開過程は明確ではなく,和名化と命名規則の関係についても必ずしも明確ではなかった。本研究の目的は,アイヌ社会における和名化の展開過程を示した上で,和名化と命名規則の関係について検討することである。
著者
山川 /修治
出版者
公益社団法人 東京地学協会
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.102, no.2, pp.183-195, 1993-04-25
参考文献数
58
被引用文献数
1 5

Natural disasters in Little Ice Age (<I>c</I>. 1550-1850) and its climatic variations which formed a significant background for the disasters are mentioned. Cool summers due to a prevailing Okhotsk High were characteristic of this period. Cold winters, summer heavy rains and unstable atmospheric conditions also constituted essential features of Little Ice Age. Aerosol ejected by a series of major volcanic eruptions partly prevented solar radiation from reaching the earth' s surface (parasol effect), which resulted in cool and unusual weather. Agriculture, in particular, was vulnerable to bad weather damage. As a result of decreasing direct insolation, sometimes together with lowering temperature and/or locally increasing precipitation, seven major famines occurred during the Edo Era (1663-1868) which approximately coincided with Little Ice Age. Several cases in this paper suggest that natural environment in Little Ice Age was marked by both volcanism and weakened solar activities which &ldquo;Maunder Minimum&rdquo;(1645-1715) represented.
著者
寺床 幸雄 梶田 真
出版者
公益社団法人 東京地学協会
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.125, no.4, pp.607-626, 2016
被引用文献数
2

&emsp;Minamata city is well known as the company town of Chisso Corporation, as the site of Minamata disease and, in recent times, as a city with environmentally friendly policies. The postwar experiences of Minamata city are often compared to a microcosm of Japanese modernization. A few decades earlier, the city faced and tackled several problems that most non-metropolitan cities currently face, such as an aging population and economic decline. There are meaningful lessons and suggestions we can adopt from Minamata city for sustainable development policies suited to non-metropolitan cities. This paper focuses on the economic history of Minamata (which includes not only Chisso but also other manufacturing companies and industries) and the dynamic relations between its local economy and politics. In Minamata, social tensions, such as those between the perpetrators and the victims of Minamata disease and between Chisso's labor and management, gradually disappeared due to reconciliation efforts and generational change. Minamata city office changed its vision of future development from being an industrial city to an environmentally friendly one, bearing in mind not only the experiences of Minamata disease victims but also the city's varied environmental resources. The residents of Minamata offered their support for these policies in recent mayor elections. Nevertheless, new problems began to emerge in the city. Jobs for the young had been limited for a long time, especially for men and those who were highly educated. One of the reasons for this is that Chisso prioritized retaining employees and restricted new hiring. Besides, the economic dominance of Chisso prevented local leaders and enterprises from growing. As a result, although Minamata's town planning, with its emphasis on environmentally friendly policies, received much attention and support, those policies could not be effectively implemented due to a lack of local human and institutional resources. Recently, however, young residents have begun to construct new social networks. It is worth noting that they share environmentally friendly visions. We can regard these kinds of movement as the results of continued efforts by Minamata city office and citizens. The economic and social dynamics of Minamata and the problems mentioned here are likely to be common to many non-metropolitan cities. Those cities must not be nearsighted about depopulation problems, but should investigate and try to maintain the conditions needed for long-term social and economic sustainability.
著者
山本 純之 磯﨑 行雄
出版者
公益社団法人 東京地学協会
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.122, no.5, pp.791-806, 2013

&emsp;Ever since the term stromatolith was first coined by Kalkowsky in 1908, research studies on stromatolites have continued for more than a century. This article reviews the study history of living and fossil stromatotelites. The history is divided into two parts by the discovery in 1961 by Logan of living stromatolites in Shark Bay, Western Australia, because this determined the subsequent main trend of studies on both living and fossil stromatolites. Major contributions during the last three decades include documentation of (1) a worldwide bloom of stromatolites in Proterozoic low-middle lateral shallow seas, and (2) oxygen-producing cyanobacterial activity related to stromatolites from the 1990s, resulting in various new aspects being clarified, which include <i>in-vitro</i> cultivation gradually revealing cyanobacterial calcification and dome-formation. Future studies will be directed towards reconciling morphological disparities and formation mechanisms among fossil, living, and cultured stromatolites.