著者

藤井 敏嗣

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.97, no.3, pp.209-213, 1988-06-25 (Released:2009-11-12)

参考文献数

22

著者

村田 明広

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.104, no.1, pp.82-93, 1995-02-25 (Released:2010-11-18)

参考文献数

24

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The Paleogene Hyuga Group of the Aradani Area in East Kyushu is regarded as an accretionary complex in the Shimanto Terrane. The Group was formerly inferred to form a melange including various sized blocks of sandstones, red and green siliceous mudstones, and basaltic volcanic rocks. The siliceous mudstones are not blocks in the melange, but occur as a low-angled thrust sheet of 40m thick.The Hyuga Group of the Aradani Area consists of four tectonic units;(1) lower chaotic unit, (2) siliceous mudstone unit, (3) mudstone unit, and (4) upper chaotic unit in ascending order. Each unit except for the siliceous mudstone unit forms a duplex structure, in which strata are imbricated, dipping 30° to 50° Each duplex is formed by mono-lithologic strata. The fundamental structure of the Paleogene Shimanto Terrane in Kyushu is characterized by low-angled nappe structures with stacked duplexes, in which duplexes lie one above the other, similarly to those of the Cretaceous Uchinohae Formation in South Kyushu.Original succession of the Hyuga Group is (1) basaltic volcanic rocks, (2) red and green siliceous mudstones of Middle Eocene, (3) black mudstones of Late Eocene, (4) sandstones and alternating beds of sandstone and mudstone of Late Eocene to Early Oligocene. Chaotic beds of melange facies originate from all above-mentioned strata. The siliceous mudstones, which are considered to be hemipelagic sediments, were subducted, and then formed a thrust sheet during underplating. The siliceous mudstones were probably situated in the decollement horizon, but did not flow as a lubricant layer.

著者

歌代 慎吉 岩淵 義郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.80, no.2, pp.77-88, 1971-04-25 (Released:2009-11-12)

参考文献数

8

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Sagami Bay is structurally active area through the geological history, and also the epicenter of the Great Kanto Earthquake (1923) was here. To make clear the features of the topography and geological structure of the active area, it seems to be fundamental step for the earthquake predication today.In April to May 1968, the surveying ship Meiyo of the Japanese Hydrographic Office carried out the sea bottom surveys of Sagami Bay with echo-sounder, seismic profiler and proton-geomagnetometer, including the dredge and coring operation, and took the data from about 3000 kilometers of her traverses.The ship's position was mainly determined by an auto-tape system with the estimated accuracy of ±2 meters. The simultaneous measurement of magnetic intensity, bathymetry and submarine geological structure by air-gun system allows direct comparison of the measurements. Figure 1 is the track chart of the Meiyo and figures 2 and 3 are some profiles based on the collected data.From the analyses of the collected data mentioned above, the topography and geological structure and magnetic anomaly of Sagami Bay can be summarized as follows.1. TopographyFigure 4 shows the bathymetric chart of Sagami Bay. In the eastern part of the bay, many banks and small basins range from NW to SE. Many submarine canyons cross the topography mentioned above and incise deeply, so that especially small basins do not keep their complete shape.The central part of the bay is called Sagami Trough, which is deeper than 1 kilometer. The floor of the trough generally shows low relief with the exception of the eastern part of the trough, which submarine canyons flow into, and gentle slope with the trend of NS at the central part, facing east and reflecting the fault topographically.In the western part of the bay, continental shelf and slope are monotonous, comparing with its eastern part. There are several conical banks between the Izu Peninsula and O Shima Island.2. Geological structureGeological structure based on the seismic profiler is shown in Figure 5. The area surrounded Sagami Bay is relatively uplifted zone in contrast with the trough showing the relative subsidence. Acoustic basement rock outcrops on the uplifted zone and may probably be composed of the Hayama group (Lower Miocene) and partly the lower part of the Miura group (Middle Miocene).The large part of the thinly layered sediment at the upper part of sediment body in Sagami Trough is younger than the age of uplifted zone mentioned above. The layered sediment is wholly tilted to the axis of the trough, and is found the folding in the margin of the trough and also the active fault near surface. Its maximum thickness is found at the northern part of the trough, and is over about 1 second in the reflection time approximately.The area along the Izu Peninsula and around O Shima Island is extensively covered with the volcanic products. Small banks between the Izu Peninsula and O Shima Island are volcanic cones of the effusive body which pierced through the layers probably composed of the Shirahama group (Middle to Upper Miocene).3. GeomagnetismThe resultant magnetic chart, contoured at intervals of 100 gammas, was in Figure 6. The results of the magnetic surveys revealed that there were many magnetic anomalies of about 500 to 800 gammas off shore along the Izu Peninsula in Sagami Bay and a pair of remarkable positive and negative magnetic anomalies of about 1800 gammas in the sea area along the west side of O Shima Island.On the other hand, it was found that there was no remarkable magnetic anomaly in the central part and eastern part of Sagami Bay.From the results of magnetic surveys and submarine geological structure, it can be concluded that the sea area off shore along the Izu Peninsula and around O Shima Island are composed of volcanic rocks of higher magnetic susceptibility, such as basalt or andesite.

著者

坂井 尚登 三浦 一彦 中西 清

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.103, no.1, pp.64-67, 1994-02-25 (Released:2010-10-13)

参考文献数

6

著者

石戸 経士

出版者

Tokyo Geographical Society

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.114, no.6, pp.885-900, 2005-12-25

参考文献数

29

被引用文献数

6 3

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Characterizing the transport properties of reservoir-forming rocks is one of the most important tasks in reservoir engineering. We review the relationships among permeability, porosity, electrical formation factor, and electrokinetic coupling coefficient under saturated and unsaturated conditions on the basis of the capillary tube model of porous medium, by which one can relate the microscopic physics of the transport properties to the macroscopic behaviors described by Darcy's and Ohm's laws and the cross-coupling effects. These relationships together with the recent models of clay rich sandstones provide a useful guideline for interpreting core, logging, and geophysical survey data. Among various rock properties, permeability in particular needs in situ measurements such as pressure transient tests, because <I>in situ</I>i values are usually at least a few orders of magnitude larger than those measured for intact core samples due to the presence of discontinuities such as fractures in reservoirs. Concerning this topic, the concept of fractured rocks, <I>i.e.</I>, the double porosity medium and how to characterize fractured reservoirs are described.<BR>Even if the results of extensive field-wide pressure transient tests are available, in addition to drilling and various exploration data, numerical models of reservoirs are never precise, due to the problem of non-uniqueness. However, once exploitation begins in earnest, additional data become available such as temporal trends in downhole flowing pressure and enthalpy (in case of geothermal reservoirs), which may be used in history-matching studies. Because uncertainty in predictions of numerical reservoir models is directly related to the amount of field data available against which the models can be tested, it is clear that the addition of repeat geophysical survey data to the list of pertinent field measurements is likely to improve the reliability of these forecasts. Recently developed computational tools such as the EKP-postprocessor, which can calculate changes in self-potential distribution through electrokinetic coupling caused by changing underground conditions computed by reservoir simulation, enable us to use geophysical monitoring data in history-matching studies.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.120, no.2, pp.Cover02_1-Cover02_2, 2011

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2010年は太平洋高気圧におおわれて8月を中心に暑さが厳しく,6月以降,東京でも最高気温が35℃を超える猛暑日が13日間,明け方の気温が25℃以下に下がらない熱帯夜の日数が56日間という記録的な高温状態が継続した.<br> 表紙写真は,都心部で最高気温が36.5℃を記録した8月15日の正午頃に,都心湾岸部の上空約5000フィート(1525m)からヘリコプターに搭載したサーモグラフィーで捉えた地表面の熱画像(放射輝度温度分布)である.なお,放射率は一律(ε=1.0)に設定し,表面材質の違いによる補正は行っていない.<br> 皇居(A)や浜離宮庭園(E)など,緑豊かなエリアが比較的低温を示すほか,南北に流れる隅田川(F)の水面が28℃以下と低くなっており,東京湾からの涼しい海風を通す「風の道」としても有効に働いていることがわかる.また,東京駅周辺(B)や汐留の高層ビル群(C)付近も比較的低温になっている.<br> 一方,湾岸の埋め立て地域や隅田川東岸に広がる密集した中低層商工業地帯の表面温度は40℃を超えている.築地の東京都中央卸売市場(D)の表面温度が高いのは,建物の屋根面の材質が影響していると考えられる.<br>(文:三上岳彦 熱画像:スカイマップ株式会社)

著者

庄子 仁 Jin Young K. Obzhirov Anatoly SALOMATIN Alexander BARANOV Boris GLADYSH Vyacheslav 八久保 晶弘 南 尚嗣 山下 総 高橋 信夫

出版者

Tokyo Geographical Society

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.118, no.1, pp.175-193, 2009-03-25

参考文献数

35

被引用文献数

5 10

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Methane hydrates exist beneath the sea bottom near cold seeps NE off the Sakhalin in the Sea of Okhotsk. Multidisciplinary field operations were performed at a study area (approximately 16 × 20 km²) to investigate seepage characteristics and understand gas hydrate formation mechanisms. A continuous profiling survey was conducted to obtain a distribution map of seepage structures on the floor by using a deep-tow, side-scan-sonar equipment. The distribution map reveals that the dense area of seepage structures coincides with a sea-floor area of deformed sediments caused possibly by repeated sediment slumping and debris flows in the past. We speculate that this deformation may have created shallow faults that are suitable to conduits for the migration and discharge of gas and fluid.<br> Three seepage structures were selected to study about their fluid-seep conditions around the sea floor level. Hieroglyph seepage structure is located at the northern end of the dense area of the structures. Kitami and Chaos structures are located about 2 and 7 km respectively apart from the Hieroglyph structure within the dense area. Large plumes on echograms and higher methane contents in the water column confirm gas seepage activities at the three structures. There observed at least two and four plumes at the Hieroglyph and Chaos structures, respectively. Each gas chimney image in seismic reflection profiles was traced to connect each BSR and seepage structure. Both pull-up and disturbed structures of BSR around the gas chimney images were interpreted as to be indications of significant heat flows caused by ascending fluid at both Kitami and Chaos structures. On the other hand, almost no pull-up/disturbance of BSR was observed at the Hieroglyph structure, suggesting little water seepage.<br> The seep activity may vary with time off the Sakhalin. The Hieroglyph structure is located at the edge of a dense area of the seepage structures. It might serve as an indicator for the long-term activity of the fluid seepage system off the Sakhalin.

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.88, no.4, pp.264-271, 1979-08-25 (Released:2009-11-12)

参考文献数

26

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.12, no.3, pp.188a-189, 1900

著者

大八木 規夫 井口 隆

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.94, no.6, pp.436-445, 1985-12-25 (Released:2009-11-12)

被引用文献数

6 9

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The main portion of Iwo-jima island consists of lava flows and pyroclastic rocks of trachy andesite, erupted and deposited in shallow sea, except the upper part of Suribachiyama, in 2600-2800 y.B.P. The island have been uplifting from about 800 y.B.P., followed by active faulting and change in coast lines.

著者

山野 明男

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.112, no.1, pp.114-130, 2003-02-25 (Released:2009-11-12)

参考文献数

23

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This research examines the development process of farming conditions of settlers in Hachirogata reclaimed land. The settlers numbered 589 in all. A total of 551 farm at present and 38 have abandoned farming.The development process of agriculture on Hachirogata reclaimed land can be divided into 3 periods : the first period -commencement of farming, the second-change in farming, and the third -settlement of farming. The development process of agriculture on Hachirogata reclaimed land (Ogata village) is shown in Fig. 7.I analyze why the 551 settlers separated into two farming groups. The results are as follows. 1) One group, 249 mainly from Akita prefecture, controls the production of rice. 2) The native places of the settlers play an important part in their division into two groups. 3) The settlers brought their native village culture into their settlement of reclaimed lands.

著者

諏訪 彰

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.89, no.4, pp.247-255, 1980-08-25 (Released:2010-10-13)

著者

藤森 孝俊 蒔苗 耕司 山口 勝 川口 隆 太田 陽子

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.99, no.2, pp.166-181, 1990-04-25 (Released:2009-11-12)

参考文献数

18

被引用文献数

1

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The 1872 Hamada earthquake (M=7.1±0.2) is one of the major historical earthquakes which accompanied a coseismic uplift and subsidence in the coastal area. This paper intends to examine an implication of the Hamada earthquake for geomorphological development of the Hamada area, based on the investigation of marine terraces, emerged sea level indicators such as sea caves, benches, fossil beds and beach deposits, and fault topography.Two steps of Pleistocene marine terraces are found in the coastal area. Terrace I, c. 40-60 m high, is underlain by weathered beach gravel covered by dune sand which is interbedded by at least four horizons of paleosol. It is considered, that a major interglacial period resulting in strong weathering of Terrace I deposits occurred after the formation of this terrace. Thus, Terrace I can be correlated to the penultimate interglacial, and Terrace II, c. 15-25 m high, underlain by rather fresh gravel bed, to the last interglacial. Accepting this correlation, the uplift rate of the study area must be small, c. 0.1-0.2 m/ka, and is no significant difference in the uplift rate over the study area. Height of emerged sea level indicators associated with the Hamada earthquake is 0.9-1.7 m above the present mean sea level. At least one sea level indicator higher than the emerged sea level at the time of the 1872 Hamada earthquake was found at several locations through the study area including the coast where coseismic subsidence occurred in 1872. Northeast-southwest trending lineaments predominate in the study area and a fault exposure is observed on one of the lineaments suggesting that they are fault origin. Areas of coseismic uplift and subsidence can be seens by turns along these faults.Characteristics of the 1872 Hamada earthquake are summarised as follows, based on the above mentioned geomorphological observation : 1) Coseismic deformation as associated with the Hamada earthquake has not accumulated through the late Quaternary, and this earthquake must be a very rare event with coastal deformation during the Holocene. 2) Distribution pattern of coseismic deformation, that is, the occurrence of small blocks with coseismic uplift and subsidence by turns can be interpreted as an effect of strike-slip movement on the faults.

著者

竹中 克行

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.121, no.4, pp.650-663, 2012

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Since its beginnings, geography in Spain has followed a particular development course, defined mainly by a close and ever evolving relationship between academic geography and professional geography. Over the last few decades, the two geographies have been mutually involved, creating a situation in which the professional practice of geography, originating with cartographers and engineers in the late nineteenth century, has become an increasingly important factor for the renewal of academic research, mostly undertaken in universities. Innovation was possible, on the one hand, thanks to the consolidation of academic geography, which today concerns not only traditional areas of knowledge, but also fields where there is growing social demand, such as environment, landscape management, regional planning, urbanism or risk analysis. All these themes, on the other hand, have opened up new professional opportunities for geography graduates, who have been contributing with their practice in administration and private enterprises to make more people aware of the importance of geography as a useful science.<br> The fruitful relationship between the two geographies briefly described above is the main concern of this article, which introduces a mixed approach of science historiography and radiography. After analyzing the evolution of academic geography through doctoral theses and major journals specialized in geography, the author highlights the role of professional geography, focusing on how geographers are entering in new fields of the labor market and are defending their interests as a professional group. The analysis is complemented by reference to successive new plans of studies launched in university geographical education, an important reform accelerated by the so-called Bologna process. The article concludes by pointing out some of the research lines that have great potential for future development with international repercussions.

著者

佐藤 暢 谷口 英嗣 高橋 直樹 Mia Mohammad MOHIUDDIN 平野 直人 小川 勇二郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.108, no.3, pp.203-215, 1999-06-25 (Released:2010-10-13)

参考文献数

65

被引用文献数

5 10

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Geological, petrological, and biostratigraphical studies of Mineoka ophiolite and related rocks, Hayama and Mineoka Belts, central Japan, were reviewed, and the origin of ophiolite is summarized as follows. 1) Pelagic to hemipelagic sedimentary rocks occur from late Paleocene to middle Miocene. 2) Basaltic rocks in the Hayama Belt are mostly alkali basalts of hotspot origin, whereas those in the Mineoka Belt are mostly tholeiite of mid-ocean ridge origin. 3) Chemical compositions of gabbros and diorites indicate island arc origin. 4) Peridotites are residues after a medium degree of partial melting. These facts arenot consistent with previous ideas that the ophiolite is island arc or back arc originonly. “It is concluded that ophiolite is part of the Mineoka plate” in the Pacific Ocean side, not in the Philippine Sea as previously proposed. Reconstruction of plate motions of the Mineoka plate is proposed, as it was formed at mid-ocean ridge, was subducted by the Pacific plate, and obducted to the Honshu arc during Miocene age after the eastward motion of the triple junction.

著者

山口 岳志

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.74, no.1, pp.34-44, 1965-02-25 (Released:2009-11-12)

参考文献数

40

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It is a common knowledge that the geography of mineral production has attracted small number of geographers comparing with other fields of economic geography. Even though there have been several articles dealing with mineral production, most of them have been concerned with either the distribution pattern of mining activities, or the commodity or commodity-in-area approach.It is, however, expected that the analysis of more dynamic characters of mineral production, which are also covered by the field of mineral economics, would bring more fundamental basis to develop this field of geography. Two factors, localized occurrence and exhaustibility, are the most important characteristics of mineral production and these must be considered as basic to the study of the geography of mineral production. In other words, the former sets the distribution pattern of mineral production, and the latter and its derivatives differentiate the pattern. The problems which stem from these two factors distinguish the mineral industries from other industrial activities.It is the purpose of the geography of mineral production to evaluate the extent and nature of the factors, to analyze the regional characteristics and to describe the areal associations brought by mining activities. In addition, some consideration should be given to the phases which the factors have brought drastic interruption in the sequent occupance of a mining region.The geographers of mineral production should pay more attention to the importance of the dynamic characters of mineral production and their associated problems and try to consider the trends of mining activities on the basis of analysis of geographical research. The rise and fall of mineral production have a close relationship with socio-economic problems of mining regions, so that the analysis of the factors appraise more fundamental understanding of the ever-increasing importance of minerals in our economy.The writer owes a debt of thanks to Dr. Shinzo Kiuchi and Dr. Osamu Nishikawa of the Department of Human Geography, University of Tokyo, for their stimulating criticisms and constructive advices. He is also deeply grateful to Dr. E. Willard Miller of the Department of Geography and Dr. John J. Schanz, Jr. of the Department of Mineral Economics for their patient guidances and kind suggestions while he was studying at the Pennsylvania State University.

著者

山口 岳志

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.74, no.1, pp.34-44, 1965

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It is a common knowledge that the geography of mineral production has attracted small number of geographers comparing with other fields of economic geography. Even though there have been several articles dealing with mineral production, most of them have been concerned with either the distribution pattern of mining activities, or the commodity or commodity-in-area approach.<BR>It is, however, expected that the analysis of more dynamic characters of mineral production, which are also covered by the field of mineral economics, would bring more fundamental basis to develop this field of geography. Two factors, localized occurrence and exhaustibility, are the most important characteristics of mineral production and these must be considered as basic to the study of the geography of mineral production. In other words, the former sets the distribution pattern of mineral production, and the latter and its derivatives differentiate the pattern. The problems which stem from these two factors distinguish the mineral industries from other industrial activities.<BR>It is the purpose of the geography of mineral production to evaluate the extent and nature of the factors, to analyze the regional characteristics and to describe the areal associations brought by mining activities. In addition, some consideration should be given to the phases which the factors have brought drastic interruption in the sequent occupance of a mining region.<BR>The geographers of mineral production should pay more attention to the importance of the dynamic characters of mineral production and their associated problems and try to consider the trends of mining activities on the basis of analysis of geographical research. The rise and fall of mineral production have a close relationship with socio-economic problems of mining regions, so that the analysis of the factors appraise more fundamental understanding of the ever-increasing importance of minerals in our economy.<BR>The writer owes a debt of thanks to Dr. Shinzo Kiuchi and Dr. Osamu Nishikawa of the Department of Human Geography, University of Tokyo, for their stimulating criticisms and constructive advices. He is also deeply grateful to Dr. E. Willard Miller of the Department of Geography and Dr. John J. Schanz, Jr. of the Department of Mineral Economics for their patient guidances and kind suggestions while he was studying at the Pennsylvania State University.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.21, no.10, pp.721-722, 1909

著者

水谷 伸治郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.108, no.5, pp.638-638, 1999

著者

砂川 一郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.96, no.7, pp.518-525, 1988-01-25 (Released:2009-11-12)

参考文献数

9