著者

柏木 洋彦 鹿園 直建

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.112, no.4, pp.473-488, 2003-08-25 (Released:2009-11-12)

参考文献数

85

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Climate change and variations of atmospheric CO2 during Cenozoic have been discussed by many studies. The model results for global carbon cycle and climate change are generally consistent with those of many analytical studies concerning climate events in early Cenozoic, e.g., early Eocene warming events. However, the climate events proposed by analytical studies in late Cenozoic are not wholly inconsistent with the results of the model studies, e.g., Miocene climatic optimum (warming), cooling events in Eocene/Oligocene boundary and middle Miocene (15 Ma). Many problems remain in relation to evaluating CO2 flux by hydrothermal solutions at mid-ocean ridges, island-arc, and back-arc basins in the models. Also, the discrepancy may be derived from errors in estimating weathering flux, organic carbon burial, and change in vegetation. Moreover, another greenhouse effect gas such as methane, land-sea distribution, albedo variations due to the formation of ice-sheets, and temperature distribution attributed to changes in the ocean circulation system should be considered. Recent analytical studies reveal that the CO2 level since Miocene has remained relatively low in spite of the suggested climate events in this period. The mechanism of oceanic environmental change, as well as atmospheric CO2, is especially important to elucidate climate change during Cenozoic.

著者

若林 芳樹 小泉 諒

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.123, no.2, pp.249-268, 2014-04-25 (Released:2014-05-16)

参考文献数

53

被引用文献数

8

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This study examines the spatial patterns of population change in the 23 Special Wards of Tokyo after the period of the bubble economy in the late 1980s. To this end, we analyze grid square data suitable for time-series analysis between 1985, when the bubble economy started, and 2005, the latest year for which data are available, using the geographic information system (GIS). After selecting major indicators representing three dimensions of the social area analysis—family status, socioeconomic status, and ethnic status—we map each indicator and make quantitative comparisons of six zones, classified by distance from the city center, and of four sectors classified by direction from the city center. The indicators used in this study are three variables representing family status (ratio of young population, ratio of elderly population, and ratio of single-person families), three variables representing socioeconomic status (ratio of blue collar workers, ratio of managers and officials, and ratio of professional and technical workers), and one variable representing ethnic status (ratio of non-Japanese people). Before analyzing these data, we examine the spatial pattern of population change in the 23 Special Wards between 1985 and 2005. This analysis reveals that a population recovery has occurred since the latter half of the 1990s in central Tokyo, where a previous population decline had continued until 1995. On the basis of this trend of population change, we examine the spatial pattern of each indicator in the social atlas. Concerning age and household composition (representing family status), spatial distribution has gradually shifted from a zonal pattern to a sectoral pattern due to the migration of nuclear families to the area surrounding the city center. The spatial distribution of socioeconomic status represented by the occupational structure maintained a sectoral pattern characterized by a contrast between the eastern and western parts of Tokyo although this distinction has blurred. In particular, the number of managers and officials in the 23 Special Wards has decreased, and the distribution shifted to a zonal pattern, which indicates a polarization of white-collar workers. The distribution of non-Japanese shows a zonal pattern in which the highest value appears in the area surrounding the city center. However, spatial autocorrelation analysis of the distribution of four major ethnic groups by nationality reveals a clustered pattern, supporting the findings of previous studies in Western countries.

著者

吉田 明夫 高山 博之

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.103, no.6, pp.696-705, 1994-12-10 (Released:2009-11-12)

参考文献数

13

被引用文献数

1 1

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We show that seismic activity decreased clearly in a wide area before the 1953 Boso-oki earthquake and the 1972 Hechijojima-toho-oki earthquake. In both cases the seismic quiescence extended to the Tokyo Metropolitan area. Marking precursory activity appeared several years before the Boso-oki earthquake in the Chiba prefecture and in the sea region off-Ibaraki prefecture. It is also noted that the seismicity in the Kanto region as well as in the sea region south off-Boso Peninsula decreased conspicuously after the Boso-oki earthquake. On the contrary an increase of the seismicity was observed after the Hachijojima-toho-oki earthquake, although deep seismic activities decreased remarkably. We show that seismic quiescences preceding the Boso-oki earthquake and the Hachijojima-toho-oki earthquake were detectable before their occurrences, and no other statistically significant quiescence has appeared in the south off-Kanto region since 1926. It is proposed that the occurrence of a large earthquake may be predicted by monitoring changes of the seismicity in a wide area.

著者

武村 雅之

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.108, no.4, pp.440-457, 1999-08-25 (Released:2009-11-12)

参考文献数

47

被引用文献数

2

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Immediately after the 1923 Kanto Earthquake (M=7.9), two large aftershocks of M=7.2 and 7.3 occurred in succession somewhere in the southern Kanto district. The first aftershock occurred about 3 minutes after the main shock and the second about 4.5 minutes after the main shock. Strong ground motions from these events and locations of their epicenters were examined mainly from data of 548 descriptions of personal experiences. It was deduced from them that shaking due to the first aftershock was severe in the Tokyo Metropolis and eastern Kanagawa prefecture. In consequence, there were many descriptions in the Tokyo Metropolis that the shaking was as strong as that due to the main shock and caused extensive damage.On the other hand, there were few descriptions for the first aftershock in the western area of the southern Kanto district, which is western Kanagawa prefecture, Yamanashi prefecture, and eastern Shizuoka prefecture. However, shaking due to the second aftershock was strong in this area. Some people living near the boundary of the three prefectures described that its shaking was as strong as that due to the main shock. Comparing the facts described in these personal experiences with the distributions of seismic intensities from other M=7 class earthquakes occurring in the southern Kanto district after the 1855 Ansei Edo Earthquake, it was concluded that the epicenter of the first aftershock was located in and around northern Tokyo Bay and that the epicenter of the second aftershock was in eastern Yamanashi prefecture. The result for the second aftershock was consistent with the epicenter determined from the seismic records by the Kumagaya Meteorological Observatory and with the epicentral distance estimated from data of S-P time at the Gifu Meteorological Observatory. The characteristics of the sequence of strong shakings within 5 minutes after the 1923 Kanto Earthquake could be elucidated in the southern Kanto district from the results of the present study.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.1, no.2, pp.70a-71, 1889

著者

青木 健一

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.111, no.6, pp.849-855, 2002-12-25 (Released:2009-11-12)

参考文献数

30

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Aspects of cultural transmission in humans are reviewed with special reference to evidence for and against vertical (parent-to-child) and non-vertical transmission. Henrich's (2001) model of biased horizontal transmission may satisfactorily account for the S-shaped adoption curves (e.g., for the spread of hybrid seed corn). The demic expansion hypothesis for the spread of early farming in Europe (Ammerman and Cavalli-Sforza, 1971, 1973) is reevaluated in the light of new theoretical results (Aoki et al., 1996). Hewlett et al.'s (2002) test of the demic expansion, acculturation, and cultural-materialistic hypotheses on 36 African ethnic groups is described.

著者

越谷 賢 丸井 敦尚

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.121, no.3, pp.421-440, 2012-06-25 (Released:2012-07-09)

参考文献数

38

---

Three-dimensional earth sciences information is being made available in digital formats because such information is useful and understandable to various users. In this study, we develop a three-dimensional hydrogeological model of Tsukuba City and the surrounding region, and develop a method for estimating the hydraulic conductivity of aquifers in combination with the three-dimensional hydrogeological model and other related hydrogeological information with the primary objective of proposing a method for evaluating groundwater resources. The three-dimensional hydrogeological model was developed using a geological map and drilling data with data interpolated using a geostatistical method. The model developed reproduced the data used well, and it was found to be accurate for practical use. Moreover, this model could be used for various types of visualization, from which information could be extracted and applied immediately to numerical simulations; this provided information that was useful and understandable for evaluating groundwater resources. The proposed method for estimating the hydraulic conductivity of aquifers was developed from hydraulic conductivities obtained from various drilling surveys, which were grouped together taking geology and stratigraphy into consideration based on a three-dimensional hydrogeological model, and using a statistical analysis. This method can be used to rapidly evaluate trends in hydraulic conductivity by integrating data distributed over a broad area. In addition, if a columnar section of an evaluated point is obtained, this method can be used to determine the actual hydraulic conductivity of aquifers. Therefore, these methods were found to be effective for evaluating groundwater resources.

著者

宮地 政司

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.59, no.3, pp.61-63, 1950

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最近測地学方面で行われた無線報時の利用による二, 三の研究成果を紹介し, 我國の無線報時の現況とその利用法の概要を述べ, それ藤広い分野を有つ地学のどこかで役立つ事を願5ものである。<BR>測定や観測を静的なものと動的なものに大別する事が出来る。歴史の示す様にそれは静から動へと発展している。近代の科学の発展はこの動的測定に負5ものが非常に多い様である。こゝでいう動的とは「時」の利用によるもので, それが無線報時の手段で簡單に自由にそして必要な精密さで利用出来る様になつたのは極めて最近でこゝ二三十年来の事である。先づ二, 三の最近の研究成果を述べてみよう。

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.3, no.7, pp.386-387, 1891

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.5, no.7, pp.356a-357, 1893

著者

福井 篤

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.73, no.1, pp.1-10, 1964-02-29 (Released:2009-11-12)

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今日, 雪氷学と称せられる分野において, 氷の結晶の問題から, 積雪・融雪の物理学的問題に至るまで, 学問的体系をととのえてきたのは, 最近ほぼ10年位の進歩によるものであろう。氷の結晶, 雪の結晶及び降雪現象については, 雲物理学の進農も含めて純基礎的学問の分野で進められてきたが, 積雪現象については, 従来主として応用科学的に取扱われ, 特に産業分野における防災対策上の問題として研究が進められてきた。特に, 多雪による大災害の発生を見ると急速にその対策研究が要望され, 昭和9年, 11年, 15年等の大雪年の際は, 農林業・鉄道などの被害が大きく, これらの分野では, 積雪による直接災害に対する対策に必要な調査研究が個々に行なわれるようになった。戦後に至ってやや暖冬の傾向にあった時期においては, 雪に対する研究調査の必要性は, 世間的に認められるところではなかったが, 産業構造の発展によって, 各分野における積は的な対策研究が進められたほか, 積雪現象の純学問的な取扱いがなされるようになってきた。近年に至り, 両者の歩み寄りが次第に深まりつつあるときに当って, 昭和35~36年の新潟における豪雪, そして今回の北陸地方から西日本一帯を襲ったいわゆる38。1豪雪となった。従来の産業分野における十数年にわたる対策研究も相当の効果があったにもかかわらず, 再度大災害をまねく結果になった。このため, 雪害対策について再び大きな話題を呼び, 多くの対策研究の再検討と同時に雪 (この場合降雪積雪現象を対象として) そのものに対する基礎的研究の必要性が論ぜられるようになった。しかしこのことを論じるに当っては, 特に38.1豪雪に際しての災害の実態が何であったか, また今日の雪に関する基礎的研究がどのような現状にあるかを見はめなければならないであろう。38.1 豪雪による災害の実態については, 各方面で調査が試みられ, それぞれの分野における被害の様相が発表されているものもあるが, 相互の関連性についての究明がなされていない面もあり, 真の意味の災害の様相がつかみにくい。また一方一般的に雪害というものがどのような形態で発生するかについてもいままで総合的に調査されたものが少なく, 社会科学に立った対策に至っては全く未開発の問題にもなっている。これらの点も考えて, 現在雪国のおかれている地理的社会的条件と雪との相互関係及びこの問題を解決する基礎的な雪そのものに関する研究との連繋について考える必要があろう。このような意味において, 雪に関する研究調査の現況と問題点を述べてみたいと思うが, 積雪学という立場における理論的発展過程については, 本誌の吉田順五先生によって詳しく述べられておるので, ここでは, 主に雪害の防災的見地に立って述べることにしたい。

著者

金 枓哲

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.121, no.5, pp.815-823, 2012-10-25 (Released:2012-12-05)

参考文献数

17

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This study reviews current trends and issues in geography and geography education in Korea. The first geographers' society was established in 1945 after the country was liberated from Japan. Despite its short history, geographical studies in Korea have sharply increased during the last 60 years. Against this background, the features of geographical studies in Korea can be summarized as follows: first, geography in Korea was required to emphasize its character as a science of the nation until the 1980s due to its geopolitical situation. Since the 1990s, however, the mainstream of geography in Korea has focused on area studies in other countries. This is partly due to the globalization of the Korean economy and an increase in the number of geographers studying abroad, especially in the United States. It should also be noted that radical geography has contributed to the linearization of Korean society since the 1980s.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.11, no.3, pp.242-242, 1899

著者

中林 一樹

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.110, no.6, pp.938-949, 2001-12-25 (Released:2009-11-12)

参考文献数

8

被引用文献数

1

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In the 21st Century, it has been announced that several earthquakes will occur beneath Tokyo Capital Region. The Tokyo Metropolitan Government implements two kinds of hazard assessments for countermeasures against the earthquake disasters. One is the disaster damage estimation for Tokyo and a disaster scenario for Earthquake that occurres just beneath Cental Tokyo. According to the Report published in 1997, approximately 378, 000 buildings will be burnt down, 43, 000 buildings will be demolished, 7, 200 people will be killed. A disturbance of the water supply will continue for one month and the interruption of piped gas will continue for two months, more than two million people will be evacuated to shelters located mainly in public schools. The other assessment concerns research on the vulnerability of built-up areas against earthquakes measured according to each community area. According to the area vulnerability research, the most vulnerable areas are located as a ring-zone around the CBD and as a finger-zone along Japan Railway's Chuo-line from central Tokyo to the west suburban region (Pictorial 4-1). These zones are made up wooden houses in crowded areas without city planning nor building permission.TMG learned much from the Kobe Earthquake of 1995 and has enlarged earthquake countermeasures to make Tokyo an earthquake-resistant city and to secure effective disaster countermeasures, quick recovery and reconstruction to protest the livelihood of the populace, and to ensure urban redevelopment. The most important measure is the Promotion Plan for Earthquake-resistant City Development Projects, because the implementation of such projects can reduce the damage in Tokyo (Pictorial 4-2). The Preparedness Plan for Urban Reconstruction is one of the new measures that was established after the Kobe Earthquake.

著者

松岡 憲知

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.121, no.2, pp.v-vi, 2012-04-25 (Released:2012-05-29)

参考文献数

3

著者

宮縁 育夫 杉山 真二 佐々木 尚子

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.1, pp.17-32, 2010-02-15 (Released:2010-05-21)

参考文献数

51

被引用文献数

10 11

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Holocene environmental changes and vegetation history are constructed using phytolith and macroscopic-charcoal analyses of a 23-m-deep drilling core obtained at the Senchomuta marsh in Asodani Valley, northern part of Aso caldera, SW Japan. An intra-caldera lake existed in the Asodani Valley prior to approximately 9 cal ka (calibrated 14C age). Multiple large flood events occurred during the period 8.9-8.1 cal ka and emplaced thick sandy deposits in the valley basin. Thereafter, the center of the Asodani Valley (northern part of caldera floor) changed to swampy and fluvial environments. sasa (cool-temperature dwarf bamboo) grasslands and/or forests with understory sasa covered slopes of the Asodani Valley basin between 11 and 9 cal ka. sasa phytoliths significantly increased at ca. 7.3-6.5 cal ka, but thereafter decreased. Miscanthus (Japanese pampas grass) grasslands existed continuously on the slopes. Macroscopic-charcoal particles were abundant during the last 6000 years, and the peak (6.1 cal ka) amount of charcoal particles is consistent with that of Miscanthus phytoliths. This indicates that the existence of Miscanthus grassland might be related to fire events. Inside the Asodani Valley, Phragmites (reed) became established continuously along the shore of the intra-caldera lake (prior to ca. 9 cal ka) and in subsequent marshes. Gramineae phytoliths were detected predominately through all horizons of the drilling core, whereas a small amount of arboreal phytolith was observed at most horizons. We, therefore, believe that forests existed on steep slopes such as the caldera wall where human impacts were small, although sasa and Miscanthus grasslands were maintained by human activity outside Aso caldera.

著者

久城 育夫

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.92, no.7, pp.508-515, 1984-01-25 (Released:2009-11-12)

参考文献数

24

著者

山本 荘毅

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.78, no.7, pp.471-482, 1970

被引用文献数

1

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Taking the good opportunity of International Symposium on Land Subsidence held in Tokyo with excursion to Osaka and Niigata from September 17 to 23 in 1969, the writer tried to review the present situation of land subsidence in the world and its related problems.<BR>He gives definition of land subsidence as the comparatively progressive sinking in a limited area due to the artificial withdrawal of fluids such as ground water, gas, oil and so on. This phenomenon is different from the slower progressive downwarping movement in a tectonic basin or relative sinking due to eustatic movement during Quaternary age with the rate of 1-3 mm per year in Japan. The rate of land subsidence may differ by as much as one or two orders in magnitude. It may also be different from more rapid collapse due to mining of coal, gold and so on. According to R. Dolzal and M. Petersen's definition, <I>subsidence, settlement</I> and <I>lowering</I> are distinguished, the writer's definition corresponds to their settlement and in some case, to lowering.<BR>He reviewed the history of study on land subsidence in Japan, and grouped them to three categories. Leveling net-work covering all over Japan was established as early as the end of 19 centuries and precise geodetic leveling has been repeated at a fixed interval. This was very useful for making clear the phenomenological aspect of land subsidence.<BR>The first researcher, who gave attention to this problem was A. Imamura with his opinion of crustal movement. In an earlier stage of this survey, his successor, N. Miyabe might have the similar opinion, but soon later noticed that its cause was the contraction of the surface soil. Among these geophisicians, K. Wadati and his collaborators pointed out that there existed a proportional relation between the rate of subsidence and that of ground water pressure changes. S. Hayami added other elements such as tidal and artificial periodic changes to this.<BR>The second group was of soil mechanicians who applied Terzaghi's theory on compaction of clay layer. Y. Ishii and his collaborators estimated future amount of land subsidence and S. Murayama conducted laboratory experiments on land subsidence. The third group which is consist of geographers, geologists and hydrologist contributed to give the fundamental knowledges, for example, F. Tada and T. Nakano supplied subsurface topography of the land subsidence areas, S. Aoki and T. Shibasaki furnished Quarternary geology of these areas and I. Kayane and the present writer discussed water balance relations of the subsiding areas. These three groups are elaborating to proceed their researches and investigations with administrative officials. Now, Japan has many observation wells in land subsidence areas. (Tab. 1) <BR>He also summarized recent trend of subsidence in Japan (Tab. 2) collecting available data on the amount and rate of land subsidences in the world (Tab. 3) and pointed out the future problems and further studies.

著者

黒田 登美雄 小澤 智生

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.105, no.3, pp.328-342, 1996-06-25 (Released:2009-11-12)

参考文献数

29

被引用文献数

9 15

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Paleoclimatic and vegetational changes during the Pleistocene and Holocene in the Ryukyu Islands were inferred from pollen assemblages. Pollen analyses of some early Pleistocene to Holocene sections in the Ryukyu Islands show several drastic vegetational changes with climatically meaningful variations.A mixed pollen assemblage containing the warm and cool temperate trees such as Cryptomeria, Abies and Tsuga, and the tropical-subtropical trees including Dacrydium, Liquidambar, , Lagerstroemia and Sapium occurred in the upper Pliocene to lower Pleistocene Shinzato Formation and the basal part of the lower Pleistocene Kunigami gravel formation. These pollen assemblages strongly support that there were high mountains over 1, 000 to 1, 500 m above the sea-level in the Ryukyu Islands in the late Pliocene to early Pleistocene. The warm and cool temperate forests in the mountainous areas were disappeared possibly by the subsidence of the basement rocks of the Islands in relation with the opening of the Okinawa Trough. Invasion of evergreen broad-leaved trees to the Ryukyu Islands in the early Pleistocene was indicated by the first occurrence of evergreen broad-leaved tree pollen in the lower Pleistocene Kunigami Gravel Formation.The pollen assemblages in the last Glacial period (ca. 22, 000 y.B.P) are dominated by the coniferous trees such as Pinus and Podocarpus, indicating that an arid climate was prevalent in the Ryukyu Islands. This evidence is consistent with the wide development of ancient dunes and paleosoil of aeolian sand origin in the islands during the last Glacial period. The pollen sequence of the uppermost Pleistocene to Holocene reveals the change of vegetation and climate from the pine forests of the late Glacial period to the climax forests of evergreen broad-leaved trees of the Climatic Optimum. It is suggested that the climatic condition in subtropical Ryukyu Islands around 20, 000 years B.P. was not so much cool but arid than the climate of the present day.

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.25, no.1, pp.67-67, 1913-01-15 (Released:2010-12-22)