著者

小口 高 斉藤 享治 原 美登里 門村 浩 林 舟

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.109, no.1, pp.120-125, 2000-02-25 (Released:2010-10-13)

参考文献数

18

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Data for Japanese alluvial fans have been made available on the Internet using ArcView IMS, a GIS-based map server software package. This system permits easy on-line browsing of the data from anywhere in the world and the creation of thematic maps at various scales for the area around an alluvial fan.

著者

早川 由紀夫 藤根 久 伊藤 茂 Lomtatize ZAUR 尾嵜 大真 小林 紘一 中村 賢太郎 黒沼 保子 宮島 宏 竹之内 耕

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.120, no.3, pp.536-546, 2011-06-25 (Released:2011-09-06)

参考文献数

11

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Two wood trunks, one charred and 75 years old and the other not charred and more than 199 years old, were collected from Hayakawa ignimbrite of Niigata Yakeyama Volcano. They were investigated using the radiocarbon wiggle-matching method to determine the age of the eruption. The result was 1225-1244 cal AD (95.4%), which is over 200 years younger than previous estimates. The eruption, including the Hayakawa ignimbrite, was the largest during the volcano's life period of 3000 years. Co-ignimbrite fallout KGc ash has been found at many archaeological sites spreading on the eastern flanks of Myoko Volcano and the Takada Plain. The age obtained here will provide a useful time constraint for archaeologists and volcanologists studying this area.

著者

林 上

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.106, no.6, pp.794-798, 1997-12-25 (Released:2009-11-12)

被引用文献数

1 1 1

著者

浦 環

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.109, no.6, pp.900-906, 2000-12-25 (Released:2009-11-12)

参考文献数

12

被引用文献数

3

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The autonomous underwater vehicle (AUV) has been recognized as a new platform for observing the underwater world. It can dive freely around the target of the mission prescribed in its computer prior to launching.Throughout a dive, it does not require the operator and the support vessel to help it to execute its mission. It has no umbilical cable, which is fitted to remotely operated vehicles currently used for underwater operations and observations and usually causes problems for the operator. This paper presents the state of the art of the AUV and how it can be used in underwater science.

著者

貝塚 爽平

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.66, no.4, pp.217-230, 1957-12-30 (Released:2009-11-12)

参考文献数

23

被引用文献数

2 2

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The northeastern part of the Kantô plain, which is the largest plain in Japan, has many terraces as shown in the geomorphological map (fig. 1).In this paper, the landdforms and the geological structures of these terraces are described as below.(1) General characteristics of the terraces.The above area is divi ed into two topographic regions by the Yamizo mountain range running from north to south. The estern part is practically made up of marine Pleistocene strata. On the other hand, the western part has many river terraces which are formed by fluvial gravels and volcanic ashes.(2) Dating of the terraces by tephrochronology (tehro means volcanic ashes).During the Quaternary period, the terraces had been covered by volcanic ash layers called Kanto Loam. Presently the older terraces and the newer ones both are covered by thick and thin Loams respectively. This relationship between terrace and Loam makes it possible to date the land surfaces chronologically. Through this the author obtained the following chronological table.(3) The river terraces built by eolian volcanic ashes.The western area is chiseled off by many river terraces. In the northern part of this terraces region, the relative heights of terrace surfaces from the preseat flood plain are higher than that of the southern part. But, if the volcanic ashes on the whole terraces are stripped off, the surfaces of the terraces have practically no significant heights, In other words, the higher the terraces, the thicker the volcanic ashes are as shown in Fig. 4, In conclusion, these river terraces would be called “Eolian volcanic ash terraces”.

著者

杉戸 信彦 松多 信尚 石黒 聡士 内田 主税 千田 良道 鈴木 康弘

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.124, no.2, pp.157-176, 2015-04-25 (Released:2015-05-14)

参考文献数

15

被引用文献数

5 8

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Spatial variations of hazards such as strong ground motion and tsunami inundation are a key element for obtaining a geographical understanding of natural disasters. However, detailed distribution of tsunami run-up heights for the devastating tsunami associated with the 2011 off the Pacific coast of Tohoku earthquake is not available. A GIS analysis of tsunami inundation areas is conducted from data collected by the Tsunami Damage Mapping Team and from post-tsunami 2-m mesh and 5-m mesh digital elevation models (DEM) after the Geospatial Information Authority of Japan, in order to produce the Tsunami Run-up Height Map, which includes polygon data of inundation areas with elevation data at each point. Horizontal shifts of orthophotos taken just after the tsunami are corrected using a Helmert transformation. The map covers Iwate Prefecture, Miyagi Prefecture, and the northern part of Fukushima Prefecture continuously at high resolutions, and reveals spatial variations of tsunami run-up heights in detail. These variations are caused by: 1) landforms at each site, such as coastal plains, valleys, bays, and beach ridges, as well as their directions and magnitudes, and 2) source locations, interference, and wavelengths of the tsunami, as implied by a previous study. The map supports examination carried out on source fault models and simulation results of tsunamis from a geographical viewpoint. At the same time, the methodology to produce the map would be useful for systematically revealing run-up height distribution, in addition to inundation areas immediately after future tsunamis.

著者

森川 洋

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.106, no.1, pp.10-30, 1997-02-25 (Released:2009-11-12)

参考文献数

27

被引用文献数

1 1

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This paper is focused on the modernizing process of urban functions in Japanese cities which should remarkably transformed since the end of feudal age ; the transformation of dominant urban functions from parasitic character through central function to management function in main cities of nonmetropolitan areas.First, examining the comparative descriptions between the end of Edo Period and the early Meiji Era mentioned in 'the Annual Report of Commercial Situation (Shokyo Nenpo)' published in 1877 and 1878, we can often reveal the properties of urban functions and urban systems in the comparative descriptions with the end of Edo Period. According to such an analysis the castle towns forming the main element of Japanese urban system in feudal age can be recognized as a kind of parasitic cities, because the merchants of castle towns mainly supplied the necessary goods to samurais inhabited in their own towns. While foods and fuels were transported into castle towns from the surrounding rural areas, the merchants of castle towns could not supply many goods with the same intensity to inhabitants of the rural areas. Besides the circulation of commodities controlled within the territory of clans, Edo (the old name of Tokyo), Osaka and Kyoto functioned as the triple centers within the whole country through oversea transportation of goods. Accordingly, the hierarchical structure of two strata can be recognized in the urban system in those days : national urban system due to the triple centers and the regional and local urban systems in clan territories. The latter usually consisted of smaller areas with castle towns as a center than in the present prefectural areas.Since the Meiji Restauration in 1868 the free economic competition has become active among cities or towns. As the merchants of castle towns lost their privileges, most of castle towns declined, at least temporally. Although there are no adequate materials to analyze central place functions, it can be estimated that they played an especially important role as urban functions in the early Meiji Era except for traffic functions because manufacturing industry has still not developed. Central place functions such as administration, education, health service, etc. were gradually established in larger centers, especially in prefectural capitals. Japanese industrial revolution occurred with singular form about from 1887 to 1907. Usually, larger centers grew and smaller ones declined, although a few new industrial towns appeared.Next, the author analyzed the branch offices of companies registered in Tokyo and Hiroshima Prefectures in 'the Main Staff List of Most Companies in Japan (Nihon Zenkoku Shohaisha Yakuinroku) in 1908 and 1935 in order to investigate firm activities in both periods. In 1908 the insurance companies located in Tokyo Prefecture already formed a network of branch offices in the main cities of the whole country including the present provincial capitals, but other firms such as manufacturing, wholesale-retail companies, etc. had only a few branch offices, mainly located in Osaka. During the period 1908 to 1935 firm activities were largely developed and the number of branch offices increased evidently.We can classify the location patterns of branch offices in those days into 4 types, apart from the present location patterns in which their location in provincial capitals is dominant : the types located 1) in large markets or large cities such as Osaka, 2) in large cities in foreign countries or colonial capitals in those days, 3) in port towns such as Yokohama, Kobe, Moji, Shimonoseki, Otaru and Hakodate, and 4) in the present provincial capitals such as Sapporo, Sendai, Hiroshima and Fukuoka. Therefore, the present provincial capitals were still not so developed for the location of branch offices in 1935 as nowadays. In the years 1908 and 1935 Kanazawa was still an significant center.

著者

佃 為成

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.99, no.1, pp.32-42, 1990-02-25 (Released:2010-11-18)

参考文献数

39

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The geologic feature of the northern Fossa Magna region is characterized by a well developed folded belt system. Recent microseismicity over 10 years and historic earthquakes reveal that there are seismic zones pararell to the axes of this structure: Itoigawa-Shizuoka Tectonic Line, the western side of Shinano River, the western margin of the Central Belt of Uplift, and the eastern margin of the Central Belt of Uplift. The last zone was recently recognized by the earthquake sequence with the main shock of M 4.9 in 1986. The fcal mechanism solutions and other geologic and geodetic evidence indicate the region is compressed in the direction perpendicular to the folded belts. We can also find seismic activity lines perpendicular to or oblique to these folding axes: the Chikumagawa Tectonic Line separates the Central Belt of Uplift with a left lateral offset of 10km; the seismic line along the eastern side of the volcanic line of Myoko-san, Kurohime-yama and Iizuna-yama makes the eastern edge of the seismic gap around the northern end of the Itoigawa-Shizuoka Line.A 20-25 years recurrence time is found in the occurrence of the major earthquake events in the central part of the northern Fossa Magna in recent 140 years.Seismic active regions are grouped into some rectangular blocks with their bases being either pararell or perpendicular to the folded belts. The activity in a block became active nearly simultaneously, and it sometimes migrated to other blocks with some delay time. The high activity migrated from the block region around the Chikumagawa Tectonic Line to both the northern activity block around the Japan Sea coast and the active region in the southern Fossa Magna during the period from 1986 to 1987.The migration of the seismic activity along the Fossa Magna region may be due to delayed transmission of the stress field in the viscoelastic or elastoviscous medium. The exponential time dependence of the decay rate of the Matsushiro swarm activity for a long period more than 20 years since 1965 is found to be reasonably interpreted by the relaxation process of stresses within the elastoviscous medium. The viscosity changed from 1.1×1019 poise to 2.7×1020 poise as time elapsed. The first value is comparable with that of a ground surface rock body estimated by secular ground tilts and strains. The latter is the same order of the values obtained in the long period second creep experiments using granite and gabbro. The Matsushiro region is one of the region where the viscosity might have been very low due to numerous micro-cracks.

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.122, no.3, pp.Cover01_1-Cover01_3, 2013

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(表面)太平洋プレート上部境界面から10km上方の曲面(地表面からほぼ40–120kmの深さ範囲)に沿うS波速度の分布(Nakajima and Hasegawa, 2010).S波速度をカラースケールで示す.太平洋プレートとフィリピン海プレートの接触域を2本の太い黒破線で囲んで示す.赤星印は1885年以降に南関東で発生した5つのM7級地震.ビーチボールは1921年竜ヶ崎地震(M7.0)(2通りの解を示す)と1987年千葉県東方沖地震(M6.7)のメカニズム解.黒丸は1987年千葉県東方沖地震の余震.(裏面)フィリピン海プレート東端部の蛇紋岩化域(茶色の領域).ピンク色の太い破線は蛇紋岩化域の西縁.フィリピン海プレート上面の深さ分布を灰色破線のコンターで示す.緑色の四角と丸は太平洋プレート上部境界面で発生した地震,灰色の点はフィリピン海プレートマントル内の地震.1921年竜ヶ崎地震と1987年千葉県東方沖地震に加え,フィリピン海プレートのマントル内の4つの地震のメカニズム解もビーチボールで示す.紫色の丸は1923年関東地震の約30時間後に発生したM7.1の余震.フィリピン海プレートはピンク色の太い破線を境にして2つに裂け,東側の蛇紋岩化域は西側の本体部分からとり残され,より遅い速度で沈み込んでいる.ピンク色の細い破線で囲んだ楕円はOkada and Kasahara(1990)が指摘した地震の空白域.(長谷川 昭)

著者

熊谷 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.108, no.4, pp.424-432, 1999-08-25 (Released:2009-11-12)

参考文献数

27

被引用文献数

9 12

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Possible tsunami deposits were found at two archeological sites along the Pacific coast near Hamana Lake in central Japan. This region has frequently suffered heavy damage from large earthquakes along the Nankai trough. Three sand deposits covering layers that include archeological remains were found at one of the sites. The ages of the sand deposits were constrained by remains just below the sand deposits, which showed good correspondence to the ages of three major historic earthquakes that seriously damaged this area, i.e., A.D. 1707, 1605, and 1498. These features strongly suggest that the sand deposits were caused by tsunami from the historic earthquakes. Core samples obtained near this site showed that a similar sequence continues into a deeper part, suggesting the existence of tsunami deposits of events older than A.D. 1498, before which few historical records are available in the Tokaido side. Further investigation of tsunami deposits in this area would yield useful information on the reconstruction of large earthquakes along the Nankai trough.

著者

矢島 道子

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.120, no.1, pp.237-238, 2011

著者

伊神 輝

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.99, no.1, pp.61-71, 1990-02-25 (Released:2010-11-18)

参考文献数

40

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Newly developed idea of the nascent plate boundary along the eastern Japan Sea has become to be discussed in the last five years. The boundary extends southwards through central Japan, where the Itoigawa-Shizuoka Tectonic Line (ISTL), one of the great tectonic lines in Japan, traverses to Suruga Bay. In the south of central Japan, the Philippine Sea plate is subducting under Japanese Islands, which lie on the North American plate and the Eurasia plate, and, therefore, a triple junction is formed there, if we acceptthe new idea of the plate boundary. Central Japan is, then, considered to be situated under the complex tectonic stress fields due to the plate interactions, and has the structures resulting from ongoing or past geodynamical process.Many seismic probings have been undertaken in central Japan and the derived structure will open informations on the geodynamic process and verifications of the nascent boundary. New resolution methods in seismic probing of the crust and the upper mantle can derive a three-dimensional velocity structure. The derived structure in central Japan, including ISTL, shows a low velocity body beneath the Hida mountains at the east of ISTL. However, the difference between the North American plate and the Eurasia plate has not beenresolved over the whole area along ISTL from the P-wave velocity of viewpoint. Many explosion profiles have been conducted in central Japan, some of which cross ISTL. The result at the north of ISTL shows a distinctive reverse fault dipping east near the Matsumoto Basin, though the fault location is slightly different eastwards from the geologically estimated tectonic line. The dip of the fault is concordant to that derived from the newidea of subducting the Eurasia plate under the North American plate. We cannot find other seismic profiles showing the similar structure in this area. In the southern part of ISTL, the northsouth fault is derived, which may be deformed by the plate interaction between thePhilippine Sea plate and the Eurasia plate.Unraveling a highly and widely resolved structure will be required to step forward to verify the new plate boundary hypothesis, and to put it practice, it is necessary to develop observation systems as well as the processing techniques. We address a request ofdeep seismic sounding which has controlled sources on a long-range profile with seismic waves penetrating deep into the crust and the upper mantle on a scale to discusss the new plate boundary hypothesis. Almost simultaneously, seismic tomography using natural sources, having a resolution of a three-dimensional image, will provide important information for better understanding of the geodynamical process in central Japan.

著者

葉 倩瑋

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.841-855, 2012-10-25 (Released:2012-12-05)

参考文献数

83

被引用文献数

1 1

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In Taiwan, geographical research, especially human geography reflects contemporary political and social changes. This paper examines the transformation of geographical research under a period of social and political changes in Taiwan. After the Japanese colonization ended in 1945, The Republic of China, led by the Kuo Ming Tang (KMT, Nationalist Party) became the new ruler of Taiwan. In 1949, the KMT moved its government to Taiwan and placed martial law. Until martial law was lifted in 1987, Taiwanese society experienced political turmoil, and the academic environment was also affected. The history of geographical research in Taiwan began in 1946, when the first geography department was established at National Taiwan Normal University (NTNU), a university that specialized in training high-school teachers. Geography came under the Department of History and Geography until 1962, when an independent Department of Geography was established. The initial mission of the department was to cultivate patriotism and loyalty to the government. The second department was founded at the National Taiwan University (NTU) in 1955 with the meteorology division under the Faculty of Science. The third department of geography was established in 1963 at a private university, Chinese Culture University, and was affiliated with the university's Faculty of Science. Two other departments were established at Changhua University of Education and Kaohsiung University of Education in the 1990s. The fact that these departments were affiliated with the Faculty of Science shaped the initial characteristics of geographical research, which emphasized the physical sciences. This bias was also rooted in the Japanese colonial period (1895-1945), because the only Japanese geographer at that time, Tomita Yoshiro, specialized in geomorphology. After Japanese colonization, those geographers who had gained advanced degrees in Japan considerable influence on research in this field. They brought the prevailing Japanese methodology of geography, particularly of geomorphology, climatology, and regional/settlement geography. This methodology was characterized by detailed ethnographic field investigation. Due to this institutional background, during the early stage of the development of geography in Taiwan physical geography was predominant, while human geography was studied only as a part of regional and industrial geography. The political situation intensified this tendency in academia; themes related to political and social issues were avoided in academic research.View PDF for the rest of the abstract.

著者

清水 正明

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.131, no.2, pp.257-274, 2022-04-25 (Released:2022-05-13)

参考文献数

68

被引用文献数

2 2

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Both the history of resource development and the progress of studies of mining and ore deposits in Japan are summarized. Researchers and engineers promoting in studies on ore deposits and resource geology are also reviewed, focusing on Professors Takeo Kato, Takeo Watanabe, Tatsuo Tatsumi, and J. Toshimichi Iiyama as well as other staffs of the Third Professorship, Department of Geology, Faculty of Science, University of Tokyo. Mineralogy, geology and geochemistry are essential for an understanding of resource geology. It is revealed that mineralogy plays an important role in studies on ore deposits and resource geology. Future directions of studies on ore deposits and resource geology are proposed.

著者

松岡 憲知 横川 美和 成瀬 元 関口 智寛

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.125, no.1, pp.7-12, 2016-02-25 (Released:2016-03-22)

参考文献数

27

著者

安里 進

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.105, no.3, pp.364-371, 1996-06-25 (Released:2009-11-12)

参考文献数

33

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Is it possible that modern Ryukyuans are the descendants of Palaeolithic Minatogawa Man, and the people of the Shellmound Period, which is partially equivalentto the Jomon Period ? There is a blank period of about 10, 000 years between the Minatogawa population and the population of the Okinawan Shellmound Period. Sakishima prehistoric culture was one of the Southeast Asian prehistoric cultures until the beginning of the Heian Period. A dramatic cultural change occurred in Okinawa after the Shellmound Period, in the Gusuku Period, which began in the 10th to 11th centuries as a result of culturalinfluence from the Mediaeval Period of Kyushu. Darling 13th to 14th centuries the culture of the Gusuku Period also expanded into the Ryukyu Islands from Amami Islands to the Sakishima Islands, and there was a general rapid population increase. Modern Ryukyuans are descended from the populations of the Gusuku Period. Some geneticists and anthropologists insists that modern Ryukyuans possess hereditary blood factors found in northern Asian populations. It is suggested that those factors flowed into the Ryukyuan population in the Gusuku Period.

著者

小林 貞一

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.89, no.6, pp.361-371, 1980-12-25 (Released:2009-11-12)

参考文献数

59

著者

篠原 叶実 伊藤 敦哉 小倉 拓郎 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.132, no.1, pp.33-55, 2023-02-25 (Released:2023-03-09)

参考文献数

69

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Marine cavernous landforms, including notches, caves, arches and tunnels, characterize the rocky coast landscape and are strongly influenced by the geology (e.g., rock strength and structure) of sea cliffs. Geological controls on the development and shape of marine cavernous landforms are evaluated based on field investigations along the Pacific coastlines of Honshu Island, Japan. Morphological parameters, width (w), depth (d), and height (h), of cavernous landforms were measured directly or through images taken with an unmanned aerial vehicle, together with geological factors, such as rock types, strength (Schmidt hammer rebound values: R), dips and strikes of bedding, major joints, and fault planes. In total, 76 caves are investigated in six coastal areas: Sanriku Coast, Joban Coast, Boso Peninsula, Miura Peninsula, Izu Peninsula, and Kii Peninsula. According to shape index, d/w, and presence of the open end, cavernous landforms are classified into notches (d/w < 1, closed end), caves (d/w ≥ 1, closed end), arches (d/w < 1, open end), and tunnels (d/w ≥ 1, open end). An analysis shows that the major geological controls differ between notches and the other three forms. Low rock strength (R < 40) and sub-horizontal bedding are, respectively, the primary and secondary controls on the formation of notches, whereas weak rock structures (joints, faults and bedding) with a dip steeper than 30° (vertical or steeply inclined structures) and a strike trending perpendicular to the cliff face are the major controls on the formation of caves, arches and tunnels. Rock strength also affects planar forms defined by the shape index, promoting a deepening of cavernous forms, particularly when the cliff has a medium rock strength (R = 30-50) that provides an optimal balance between erosion force and resisting force. In general, vertical or steep structures contribute to the deepening of holes, whereas horizontal or gentle structures favor widening.

著者

大村 纂

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.4, pp.626-634, 2012-08-25 (Released:2012-09-03)

参考文献数

20

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The article presents a summary of the development of geography in Switzerland since the late 19th century. After initial development placed weight on physical geography, there was a period after the Second World War until the early 1970s when human geography blossomed, mainly because of the need for regional planning. During the 1970s, geography in Switzerland searched for a new direction either as an environmental science or as a part of the Earth sciences. In a method-oriented development, satellite-based remote sensing and computer-based Geographic Information System were actively introduced. During the last thirty years, the field of physical geography has been productive, while human geography has failed to establish itself either as an environmental science or a scientific discipline with a global perspective. Notable accomplishments at universities in Berne and Zurich, as well as at the Federal Institute of Technology (E.T.H.), are summarized. Coordinated contributions that are internationally acknowledged have been made in various fields of climatology and geomorphology. Furthermore, the teaching of geography at Swiss high schools and teaching training methods at universities are outlined.

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.125, no.1, pp.Cover01_01-Cover01_02, 2016-02-25 (Released:2016-03-22)

参考文献数

1

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層状堆積岩層を切って崩壊地―ガリー―土石流錐の一連の地形が形成されており,その下端は多角形土のみられるクレーター底(写真右端)に張り出している.斜面頂部(写真左端)にも多角形土が広がる.これらの景観より,高緯度に広く存在する「氷に富む表層(永久凍土)」からなる谷頭部で(融解?)侵食が発生し,土石流の流下によりガリーを発達させ,斜面基部に堆積するという地形変化が最近も起こっている可能性がうかがえる.崖錐表面は季節的なドライアイス層で覆われて白っぽくみえる.HiRISEのホームページにGulick(2014)による本画像の紹介記事がある.写真の左右幅は約5 km.(写真提供:NASA/JPL/University of Arizona;説明:松岡憲知)