著者

松岡 憲知 今泉 文寿 西井 稜子

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.122, no.4, pp.591-614, 2013-08-25 (Released:2013-09-11)

参考文献数

127

被引用文献数

5 6

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This review paper synthesizes geomorphic dynamics, sediment transport and resulting natural hazards in mountains of the southern Japanese Alps and their drainage basins, where climatic and geological situations produce highly active landform dynamics. In alpine areas above the timber line, shallow diurnal freeze-thaw action operating in the thin topsoil produces small-scale periglacial forms, and gravitational spreading leads to numerous sackung features where snow-melt and heavy rain in places promote rockslides. In subalpine and montane areas, deep-seated landslides originate from fractured sedimentary rocks, deep V-shaped valleys, and heavy rain, while shallow landslides continue with historical forest clearance. Continuous slope failures prevent vegetation recovery and maintain debris input to valleys. Steep valleys contribute to high-density debris flows. Frequent or repetitive occurrences of these mass movements promote continuous denudation of slopes, rockfall accidents along hiking trails, and sedimentation at artificial dams. They occasionally cause significant hazards to villages further downstream. Predicting and mitigating slope hazards require distinguishing among annual, low-magnitude processes, episodic high-magnitude processes and geomorphic changes associated with long-term climate change.

著者

中西 正男

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.126, no.2, pp.125-146, 2017

被引用文献数

4

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<p> A newly compiled bathymetric map including parts of the Kuril, Japan, and northern Izu–Ogasawara trenches in the northwestern Pacific Ocean demonstrates that most bending-related topographic structures are limited to less than 80 km from the trench axis. This observation contrasts with one that bending-related structures of eastern Pacific trenches are limited to less than 50 km from the trench axis. The discrepancy may be due to differences in the ages of subducting oceanic plates. Bending-related topographic structures of the western Kuril and southern Japan trenches are not parallel to the trench axis, but instead are parallel to magnetic anomaly lineations. Those of the northern Izu–Ogasawara Trench are parallel to fracture zones. These observations indicate the rule that the inherited seafloor spreading fabric is reactivated instead of forming new faults when the degree of obliquity between inherited seafloor spreading fabric and trench axis reaches about 30°. This rule is applicable to most trenches around the Pacific Ocean, except for some parts of curved trenches and trenches near seamounts or other volcanic edifices constructed by off-ridge volcanism. Most bending-related topographic structures near off-ridge volcanic edifices are parallel to the trench axis. This observation suggests that inherited seafloor spreading fabric around the volcanic edifies was disrupted by volcanism.</p>

著者

杉本 興運 小池 拓矢

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.124, no.6, pp.1015-1031, 2015

被引用文献数

4

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&emsp;This study examines tourist behavior in the Mt. Fuji area in terms of distance traveled by tourists, and clarifies differences in types of tourist and their movements based on distance traveled. Moreover, it describes the social impact of the area's recognition as a UNESCO World Heritage site on the behavior of tourists. Tourism in the Mt. Fuji area began as Fuji Tohai, which means &ldquo;climbing for worship&rdquo; in the Edo era, and was popularized by subsequent tourism development. At present, the Fuji area is a tourism region that provides opportunities for sightseeing, leisure, and recreational activities, such as exploring and staying in the Fuji Five Lakes region, to visitors who live in or near urban and metropolitan areas. By analyzing the results of a questionnaire survey given to domestic individual travelers who use private cars, we found that their behavior is characterized by differences related to travel distance, although most of them share the common purpose of experiencing natural landscapes during their travels. Neighborhood residents tend to visit for daily leisure activities, whereas visitors from distant places tend to make overnight trips and visit only major tourist attractions. This shows the nature of the concentric model, which means that travel distance influences the behavior of tourists, their perceptions, and frequency of trips, and vice versa. However, we simultaneously discovered a distortion in this model, which is caused by the locality of the Mt. Fuji area. Tourism in the Mt. Fuji area currently faces changes resulting from the significant social impact of the area's recognition as a World Heritage site: Tourism demand is increasing, especially among persons who live in more distant places, which means foreigners living abroad in this study, and local residents are working to develop tourist areas and touring routes, focusing on World Heritage. Tourist behavior, such as perception and movements, have gradually changed in parallel with social and environmental changes.

著者

川畑 幸夫

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.61, no.4, pp.121-125, 1953

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In this paper the author summarized the researches done in Japan on the relation between sunspots and meteorological phenomena.<BR>The idea common to almost all the researchers is that the sunspots as an index of solar activity cause the variations of atmospheric pressure on the earth namely, as the conditions of the earth's atmosphere which receives solar radiation are varying according to seasons and locations, the changes in solar radiation due to sunspots cause the variations of the distribution of atmospheric pressure, which result in disturbances of air currents and in climatic variations. And these disturbances are almost strongly effected, in Japan, by the changes in the intensity of the North Pacific High and by the migration of its center.<BR>A few Japanese researchers are making use of the faculae instead of sunspots in their researches, and they consider the degree of the faculae's facing to the earch as the solar activity index, and this consideration seems to be an excellent one perhaps unseen in other countries.

著者

河本 大地

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.6, pp.Erratum6_2, 2011-12-25 (Released:2012-01-28)

被引用文献数

1 1

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地学雑誌120巻5号(2011)掲載の河本大地著「ジオツーリズムと地理学発『地域多様性』概念―『ジオ』の視点を持続的地域社会づくりに生かすために―」(p.775-785)に誤りがありましたので,お詫びし訂正いたします。p.777 左段24行:(誤)尾形 → (正)尾方p.784 文献表:(誤)尾形 → (正)尾方

著者

松岡 憲知 小口 千明 福士 圭介 松四 雄騎 横山 正

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.126, no.3, pp.267-269, 2017

著者

松岡 憲知 小口 千明 福士 圭介 松四 雄騎 横山 正

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.126, no.4, pp.409-411, 2017

著者

立平 良三

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.111, no.5, pp.780-782, 2002-10-25

参考文献数

4

著者

鈴木 眞静

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.22, no.5, pp.370-375, 1910-05-15 (Released:2010-10-13)

著者

望月 公廣

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.126, no.2, pp.207-221, 2017-04-25 (Released:2017-06-12)

参考文献数

39

被引用文献数

2 3

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Seismicity accompanying subduction of one plate under the other is active in subduction zones. This seismicity is not uniformly distributed along strike; aseismic regions may be identified in a band of active seismicity. Such an uneven distribution may be attributed to the heterogeneity of frictional properties along the plate interface. Variations in the physical properties of the top-most layer over the subducting plate and rough topography along the plate interface are considered to be factors determining frictional properties. Recent active-source seismic surveys have revealed characteristics of the plate interface in detail and provide an understanding of how regional seismicity and slip distributions of major earthquakes are controlled. Seismicity around the northern limit of the 2011 Tohoku-oki earthquake shows a good correlation with seismic reflectivity along the plate interface, and suggests that the water content and/or the amount of clay minerals in a thin layer over the top of the subducting plate is a major factor. A subducting seamount was identified from a seismic survey around the southern limit of the 2011 Tohoku-oki earthquake off Ibaraki Prefecture. Repeating M 7 earthquakes share the same source at the subduction front of the seamount, while the source area of the largest aftershock of the 2011 Tohoku-oki earthquake lies next to it. The fault slip of these earthquakes, once initiated at the base of the seamount, did not propagate over the seamount. The same relationship between fault slip and subducted seamount is identified for a large slow slip at the Hikurangi margin. Physical or structural properties controlling seismicity or fault slip along the plate interface appear to be characteristics of the subducting plate. The importance of geophysical surveys of the incoming plate can now be further emphasized to provide a better understanding of seismicity along the plate interface.

著者

中田 節也

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.105, no.2, pp.244-245, 1996-04-25

著者

安里 進

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.105, no.3, pp.364-371, 1996-06-25

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

王 天天

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.129, no.1, pp.1-19, 2020-02-25 (Released:2020-03-17)

参考文献数

61

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During the past few decades, China has experienced several institutional changes, which have provided a distinctive background for its urban spaces to restructure. In the planned economic era, despite the strong influence of the USSR, the unique “Danwei” system was created to reflect the state of affairs of the country. A Danwei or work unit is not only a place of employment, but also provides welfare benefits such as housing, education, and health care for employees and their families. Workplace, housing, and facilities needed for daily life are usually built inside one gated enclosure, a Danwei compound, which became the basic spatial unit of urban China. Such proximity between workplace and residence indicates that a clear suburban residential area in the Western sense had not existed during the pre-reform era. Thus, urban spaces were formed to a unique cellular structure, which distinguishes itself from not only models considered in Western cities, but also socialist cities in Eastern Europe. Following reforms and opening-up, the land market started to develop from the late 1980s. Spatial differences in land prices led to a massive shift in land use, including the relocation of low-profit factories away from city centers, and the emergence of central business districts in big cities. In the late 1990s, the commercialization of housing was promoted. Welfare housing allocated by Danwei has been converted into private ownership, and suburban areas started to spring up with the new construction of commoditized housing. Under this process, a separation between home and work started to take place in urban China. Thus, suburban residential areas in the Western sense, with residents commuting long distances to a city center, have finally come into existence. However, due to government regulations on the development of low-density detached housing, this emerging suburban growth is dominated by mid- to high-density collective housing developments. In this sense, it is inaccurate to claim that residents of suburban China changed their ways of living to the distinctive suburban lifestyles found in “typical” Western or Japanese suburbs.

著者

福井 幸太郎

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.111, no.4, pp.564-573, 2002-08-25

参考文献数

29

被引用文献数

2 2

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A pit survey, near-surface ground-temperature monitoring, DC resistivity tomography, and an eighteen-year interval survey elucidate the internal structure and the recent movements of the active protalus rampart in the Kuranosuke Cirque, the northern Japanese Alps. Permafrost was found beneath the lower part of the protalus rampart by using ground temperature monitoring and DC resistivity tomography. The results of DC resistivity tomography suggest that the materials of the protalus rampart has a at least 15 m in thickness. Four targets placed on the lower part of the protalus rampart moved at mean horizontally rates of 2.4 to 7 mm a<SUP>-1</SUP> between 1983 and 2001. These displacements probably occurred due to permafrost creep and/or deformation in the lower part of the active layer.

著者

金光 玄樹 下條 将徳 平田 岳史 横山 隆臣 大藤 茂

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.6, pp.889-909, 2011-12-25 (Released:2012-03-05)

参考文献数

65

被引用文献数

4

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We measured the LA-ICP-MS U-Pb age distribution of detrital zircons in three psammitic schist samples of Hitachi and Nishidohira medium P/T metamorphic rocks from the southern part of Abukuma Belt, Northeast Japan. It has been proposed that these medium P/T metamorphic rocks mark the eastern extension of the Triassic collisional suture between the North China and South China blocks. Therefore, we aim to obtain the age of sedimentation, stratigraphy, and provenance of their protolith from the measurements, and evaluate the above proposition. The psammitic schist sample (DIO-9) of Hitachi Metamorphic Rocks, originating from quartzose sandstone at the lowest part of the Daioin Formation, contains detrital zircons of the youngest age clustered around 410 Ma and the youngest zircon at 395 ± 20 Ma (206Pb/238U age; 2σ). Considering that the upper part of the Daioin Formation contains Visean (Lower Carboniferous) corals and that the formation intercalates abundant felsic tuff layers, the lowest part of the Daioin Formation is likely to be correlated with Devonian Nakasato or Lower Carboniferous Hikoroichi Formation of South Kitakami Belt, Northeast Japan. Nishidohira Metamorphic Rocks lie beneath ultramafic rocks along the base of Hitachi Metamorphic Rocks, and consist of mafic, siliceous, calcareous, pelitic, and psammitic schists or gneisses. Because the siliceous schist of Nishidohira Metamorphic Rocks is meta-pelagic chert, the metamorphic rocks presumably originated from an accretionary complex. The ages of detrital zircons in two psammitic schist samples (ND-12 and -13) of Nishidohira Metamorphic Rocks mostly fall between ca. 300 Ma and 200 Ma, with the youngest two zircons at 154 ± 6 Ma (ND-12) and 175 ± 3 Ma (ND-13) (206Pb/238U age, 2σ). The protolith age of the psammitic schists must be ca. 154 ± 6 Ma (Kimmeridgian of Late Jurassic) and ca. 175 ± 3 Ma (Aalenian of Middle Jurassic) or younger, suggesting that Nishidohira Metamorphic Rocks originated from a Jurassic accretionary complex. In the Hitachi area three tectonostratigraphic units superpose, i.e., in ascending order, (1) the Jurassic accretionary complex of Nishidohira Metamorphic Rocks, (2) ultramafic rocks, and (3) Hitachi Metamorphic Rocks that are at least partly correlated with the Paleozoic sequence of South Kitakami Belt. The tectonostratigraphy is similar to that of non-metamorphic rocks of Kitakami Mountains, Northeast Japan, where (1) the Jurassic accretionary complex of North Kitakami Belt is overlain by (2) the Hayachine mafic–ultramafic complex, which in turn is overlain by (3) the Paleo–Mesozoic succession of South Kitakami Belt.

著者

副島 八十六

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.15, no.11, pp.840-857_1, 1903

著者

副島 八十六

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.10, no.9, pp.488-499, 1898

著者

副島 八十六

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.10, no.10, pp.531-542, 1898

著者

三上 岳彦 財城 真寿美 平野 淳平 森島 済

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.127, no.4, pp.443-446, 2018-08-25 (Released:2018-10-05)

参考文献数

15

被引用文献数

1

著者

LePichon Xavier 飯山敏道 RENARD Vincent 中村 一明 CADET Jean-Paui 小林 和男

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.93, no.7, pp.442-454, 1985