著者

西尾 嘉朗 佐野 有司

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.109, no.4, pp.636-645, 2000-08-25 (Released:2010-11-18)

参考文献数

24

被引用文献数

1

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Based on δ 13C values and CO2/ 3He ratios of North Fiji Back-Arc Basin basalt glasses, wediscuss the carbon geochemical cycle in the subduction zone. Among the North Fiji Back-ArcBasin basalt glasses, there is a close correlation among CO2/ 3He ratios, δ 13C value, and143Nd/ 144Nd ratios. The CO2/ 3He ratios and the δ 13C values of North Fiji Basin basalt maybe attributed to binary mixing between the mantle component (low-CO2/ 3He, high-δ 13C, andhigh-143Nd/ 144Nd) and the subducted (recycled) component (high-δO2/ 3He, low-δ13C, and low-143Nd/ 144Nd). From a simple mass balance calculation, it is derived that the subductedend-member (recycled carbon) has 70% carbonate and 30% organic matter in origin.Assuming that complete decomposition of the subducted organic matters has occurred, most (about 90%) carbonates are not decomposed, because the amounts of subducting carbonatesand organic matters throughout the North Fiji subduction zone are estimated in a ratio of20: 1. This suggests that carbonate can be transported into the mantle through the subduction zones.

著者

横山 又次郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.44, no.2, pp.61-67, 1932

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更新世中に猿人と今の人類と相異る人類との産した後、その末季に當つて出現した人類がある。之をホモ・サピエンス・フヲッシリスと稚へて、今人の亞種と見倣さるゝ者である。而もそれは一でなく三ある、日ぐオーリニヤック曰くグリマルヂー、曰くクロマニヨンである。中でクロマニヨン種は惜に前の二種より時期上晩生の春である。但し三者其に人類學者の所謂奮石器時代と稽する時期の後半中に隊洲に蔓延してゐた者である。

著者

河角 広

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.79, no.3, pp.115-138, 1970-06-25 (Released:2009-11-12)

被引用文献数

7 13

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In earlier days most Japanese wanted eagerly to have means of earthquake prediction in order to escape earthquake disaster taking refuge in advance in open spaces since they were almost powerless in encountering the menaces. We are now enabled to long for the mitigation of the disaster by the advancement of science and technology, although we have not yet succeeded to predict the coming of a disastrous earthquake. Our safety thus depend entirely on our effort for the countermeasures against the calamity. But we have only limited allowances for such preparations economically and in time available. It is therefore inevitable to start the preparation from the most important and imminent localities in a country, from the national point of view.In Japan, according to the writer's witness on the imminence of Southern Kwanto District at the Diet in July, 1964, such preparation work for Tokyo Metropolis was started the next month by a new Earthquake Division of the Disaster Prevention Council of the Metropolis, and several important hazard possibilities of the imminent earthquake have been revealed with the result that similar committees have also been made in other prefectures and cities in the same area as well as in the Central Government of the country.In this paper the writer intended to give the ground for his assertion of the imminence of a disastrous earthquake giving proofs of the periodicity of such calamities on the statistical and historical analyses, and made some comments on the possible consequences and major problems in the countermeasures to cope with the conceived disaster as revealed by the studies made on the national and metropolitan levels.In view of the importance, interest and the space allowance, only the proofs of the periodicity in the recurrence of destructive earthquakes in the district concerned are summarised in this abstract.Historical earthquakes in and around Kwanto District as shown in the map (Fig. 2.1) were examined and those which were destructive at Kamakura or presumable as such from the standard intensity-distance-magnitude curve were selected and listed in Table 1.1. Periodicities of these earthquakes were analysed statistically. Similar analyses were also applied to the earthquakes experienced in Tokyo which are listed in Table 2.2. A definite period τ of 69 years (besides a few integral multiples of this period) was clearly found. The methods used in the above analyses were by means of (1) Fourier transforms (Fig. 1.1), (2) autocorrelation functions (Figs. 1.3 and 1.4) and (3) historical examinations of the number of cases when no destructive earthquakes took place within the standard deviation +√ ξ2 from the year tp when a destructive earthquake was expected to occur from the periodicity. Test of persistence of the period was also made by means of the theory of random walks consisting of Fourier amplitudes in successive periods (Figs. 1.5 a and b). Rayleigh-Schuster's criterion (Formula 1.3) that is the probability of obtaining the actual Fourier amplitude on the assumption of no periodicity or the resultant distance of above mentioned random walks gave the values of the probability equal to 0.06% and 0.03% for Kamakura and Tokyo respectively. In comparison to usual value of 5 or 10% for recognizing periodicity in geophysical phenomena, the smallness of the above values is more than enough to disprove the non-existence of the periodicity of 69 years in the recurrence of destructive earthquakes in the districts under consideration.

著者

田中和広

出版者

東京地学協会

雑誌

地学雑誌

巻号頁・発行日

vol.118, no.3, 2009

著者

小野 晃

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.533-541, 1984-01-25 (Released:2009-11-12)

参考文献数

12

著者

新藤 静夫

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.78, no.7, pp.449-470, 1970-01-25 (Released:2009-11-12)

参考文献数

32

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1) 本地域の地下地質層序は下位より三浦層群下部, 同上部, 東京層群下部, 同中部, 同上部, 武蔵野礫層以上であつて, それぞれの関係は深井戸資料, 電気検層資料, その他によつてかなり正確に識別できる。またこれらは周辺地域における従来の知見ともほぼ一致する。2) 本地域における三浦層群は大きく北東に向かつて緩傾斜をなす向斜状の撓曲構造を示し, 関東造盆地運動の性格をよくあらわしている。そしてこの向斜構造に伴つて大構造の傾斜方向を軸とする顕著な波状構造がみとめられる。3) 以上の地質構造を形成した地殻変動は本層群の堆積中から継続的に行なわれていたと解される。4) 三浦層群の上面には旧河道に相当すると考えられる北東方向の谷地形が形成されている。東京層群下部層はこの凹地を埋積して分布している。なおここにみる地下谷の延長を周辺の丘陵地域にのばすと, 現河川で一致するものが多く, その原型の形成が古いものであることが推察される。5) 上記の地層群を覆つて扇状地性の堆積物と考えられる礫質の地層が広く分布している。これが東京層群中部層であつて, 本層の下底部にも北東方向の顕著な谷地形がみとめられる。6) 三浦層群の上面と東京層群下部層の上面にみとめられる谷地形がともに三浦層群の構造とよく一致している事実から, 三浦層群の地質構造を支配した造構造運動は継続してそののちの地形の形成に影響をおよぼして来たことが推察される。7) 上記の地層の上位に東京層群上部層が重なつている。この地層はかっては, 武蔵野台地の全域を覆つていたと考えられるが, 現在ではその大部分が浸食によつて欠如していて, その分布が武蔵野台地の東縁部と西端部地域の地下に限られている。周辺の所沢台, 金子台, 日野台等を構成している段丘礫層は本層の延長に相当すると考えられる。8) 東京層群中部層上面の地下谷の分布とこれを埋積する東京層群上部層の層相から, 少くとも武蔵野礫層の堆積以前は当地域の水系は継続的に北東ないし, 東北東方向をとつていたものと考えられる。9) 多摩川が現在のような流路をとるにいたったのは上記の水系を強制的に変えるような運動があつたためである。この地変は武蔵野台地の北西部が南東部に対して相対的に上昇するような地盤の傾動であつたと考えられる。そして武蔵野段丘や立川段丘の形成にはこのような地盤の傾動も関与している可能性がある。10) 武蔵野台地の北西部付近での三浦層群の傾斜, 東京層群下部層および中部層の基底部の傾斜がいずれも他にくらべて異常に大きいというのもこの推定をうらづける資料としてあげることができる。

著者

鈴木 毅彦

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.116, no.3, pp.Plate1-Plate2, 2007

著者

長岡 信治 新井 房夫 檀原 徹

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.121-152, 2010-02-15 (Released:2010-05-21)

参考文献数

75

被引用文献数

5 7

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The study investigates the past 1 Ma tephrostratigrapy of the Miyazaki plain in southern Japan. There are over 50 tephra layers, 80% of which originate from Kirishima volcano 25 km west of the plain. Several widely spread marker tephra layers in the layers and fission-track dating are used to establish tephrochronology. The explosive eruptive history of the volcano was reconstructed on the basis of tephrostratigraphy and tephrochronology. The history has two volcano groups: Pre-Kirishima 900-600 ka and Kirishima 600-0 ka. Pre-Kirishima volcanoes are unknown in detail. Kirishima volcano is divided into the Older Kirishima volcano, 600-330 ka, and the Younger Kirishima volcano, 330-0 ka. The Older Kirishima is characterized by calder-forming eruptions and large-scale pyroclastic flows, > 100 km3 in volume. Older Kirishima consists of four stages: O1 (600-530 ka), O2 (530-520 ka), O3 (520-340 ka), and O4 (340-330 ka). The tephra of O1 includes over five crystal-enriched ash fall layers, which indicate that vulcanian and phreatomagmatic eruptions occurred intermittently at that stage. O2 is the first calder-forming stage, in which the Kobayashi-Kasamori pumice fall and pyroclastic flows and Kobayashi caldera were formed. The pumice falls and a co-ignimbrite ash fall of the pyroclastic flow were dispersed over 1000 km east of the source, and covered the western half of the main island of Japan. O3 tephra layers are composed of over ten tephra layers formed by intermittent plinian and phreatomagmatic eruptions. The latter indicates that lakes emerged in the caldera. O4 stage is a large-scale eruption with the Kakuto pyroclasatic flow and Kakuto caldera forming. The Kakuto pyroclastic flow was accompanied by a pumice fall and a scoria fall. They were small-scale scatterings near the source from small-scale eruptions, while the co-ignimbrite ash fall reached Kanto, which is 1000 km east of the source. The Younger Kirishima began with intermittent pumice and scoria falls soon after the O4 stage. The Younger Kirishima forms the main landform in the Kirishima volcano. Most of the Younger Kirishima tephra layers of more than twenty scoria and pumice falls were caused by plinian and sub-plinian eruptions accompanied by lava flows. The activity of the Younger Kirishima volcano is subdivided into four stages: Y1 (330-130 ka), Y2 (130-50 ka), Y3 (50-30 ka), and Y4 (30-0 ka) on the basis of thick soil and erosive horizon, which suggest quiet volcanic activity with no eruptions or only lava flow eruptions. Y1 includes over five tephra layers from sub-plinian eruptions in the western part of Kirishima volcano. There is a long quiet period between 240 ka and 130 ka. Y2 has six scoria falls, which show sub-plinian eruptions in the western part of the volcano. Y3 tephra is composed of Uchiyama pumice fall, Iwaokoshi pumice fall, and Awaokoshi scoria fall. Iwaokoshi from Onaminoike 40 ka old and Awaokoshi from Hinamori-dake 30 ka old, were much larger eruptions than other tephra of the Younger Kirishima volcano. Forming stratovolcano at the source, they reach the Pacific Ocean and Miyazaki plain 50 km east of the source, while most of the Younger Kirishima tephra are distributed near Kirishima volcano. Y4 has more than ten pumice, scoria, and ash falls, which include historically recorded tephra layers. Of them, the Kirishima-Kobayashi pumice fall from Karakuni-dake 16.7 ka spread over the widest area, covering half of the Miyazaki plain and reaching the Pacific Ocean.

著者

澤田 結基 武田 一夫 川辺 百樹 藤山 広武

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.5, pp.853-863, 2011-10-25 (Released:2012-01-17)

参考文献数

12

被引用文献数

4 8

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We conducted an experimental geotour, which was monitored by professional nature guides, to improve our geotour plan and guiding techniques. We asked the nature guides to fill out a questionnaire and give advices to improve the geotours. The experimental geotours were conducted at the Shikaribestu volcano group and Shikaribetu Lake in central Hokkaido, Japan. We explained the geological history of the volcano group and the mechanism of cold talus slopes filled with ice, in as simple terms as possible. However, the nature guides judged our geotours to be “rather difficult”, indicating that our plan and interpretation need to be improved. Based on the results of questionnaires and comments from the nature guides, we propose some ideas to improve the geotour in general: (1) Eliminate technical terms where possible in the explanations; (2) Use clear figures and pictures in explanations; and, (3) Make a story to connect all the geosites included in a tour. To improve guidebooks: (1) Use bird's-eye view map or other 3D maps instead of contour maps to make it easy to understand the landform; (2) Add glossary of technical terms and scale of geologic time; and, (3) Send the guidebook to participants before the geotour. These ideas may help to deepen the participant's' understanding and to achieve high-level of satisfaction among participants.

著者

岩間 英夫

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.106, no.1, pp.87-101, 1997-02-25 (Released:2009-11-12)

参考文献数

31

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This study attempts to identify internal formation processes of the Muroran steel industrial community by complex steel mills in Hokkaido, the first iron-works of private enterprise in Japan.It then constracts an internal formation process of single manufacturing communities by comparing Muroran with the Kamaishi iron mining-manufacturing region in Iwate Prefecture, the Ube coal mining-manufacturing region in Yamaguchi Prefecture, and the Hitachi copper mining-electrical manufacturing region in Ibaraki Prefecture.The results of the study are summarized as follows.1) Internal formation processes of the Muroran steel industrial community has lead to the following results.1. Muroran started its business as a modern steel industry. Manufacturing community of the Nippon Steel Works consists of a company community and the surrounding affiliated community. A company community of the Nippon Steel Works formed a unipolar concentric zonal structure, in which a productive, a commercial service, and a residential functions were located around the office. The Muroran ironworks formed manufacturing community of a unipolar zonal structure. A unipolar concentric zonal structure corresponds with the cases of Kamaishi, Ube and Hitachi.2. Muroran formed manufacturing city of multipolar zonal structure with two company communities.3. When the system of making steel from are in the same plant was introduced, the Muroran iron works community grew into twice the size while maintaining a unipolar concentric zonal structure. It is termed an expanded unipolar concentric zonal structure. Muroran formed manufacturing city of a multi-expanded polar concentric zonal structure with two company communities.4. A expanded polar concentric zonal structure of the Muroran iron works grew and included a unipolar concentric zonal structure of the Nippon Steel Works. It is formed a core concentric zonal structure. By the enlargement of a productive functions, commercial service and residential districts was spread into the surrounding community. As a result, Muroran formed large manufacturing city of a core concentric zonal structure.5. The steel industry declined. But residential districts was expand into the surrounding community, because both employees and retired peoples established their own houses on the outskirts, resulting in the expansion of urbanized area. The affiliated community on the central lowland grew into the Central Business District. Muroran formed city.6. The above analyses lead to an internal structure model of the Muroran single miningmanufacturing community as proposed in Fig. 5.2) The comparison of Muroran with the Kamaishi, Ube and Hitachi has lead to the following results.1. Whereas Ube and Hitachi have developed from a unipolar to a multipolar and to a core concentric zonal structure, steel industry communities experienced different stages. Kmaishi, restricted by topographical features, stays in a unipolar concentric zonal structure, Whereas Muroran with a enough space developed from a unipolar to a core concentric zonal structure.2. A expanded polar concentric zonal structure was caused by the establishment of the system to produce steel from ore in the same plant. This structure shares an essentially same character with a unipolar concentric zonal structure. Therefore, general internal formation process of single manufacturing communities developed basically from a unipolar concentric zonal structure, to a multipolar and to a core concentric zonal structure.3. The internal formation process model of a single manufacturing community by complex steel mills is proposed in Fig. 6.4. An internal formation process of a single manufacturing community by a steel industry is summarized into Fig. 7-A, while the model of complex steel mills is proposed in Fig. 7-B.

著者

植村 癸巳男

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.45, no.11, pp.520-533_1, 1933

著者

有馬 貴之 青山 朋史 山口 珠美

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.6, pp.871-891, 2016-12-25 (Released:2017-01-25)

参考文献数

25

被引用文献数

2 3

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Geoparks in Japan conduct several educational programs mostly for elementary and junior high school students, teaching geology and geography. Staff in geoparks teach local geology and geography; however, there are no programs for tourism education. Besides, most are for elementary and junior high students. Hakone geopark has assisted several schools in their educational programs through museums and delivery classes. Two tourism education programs in Teikyo University are presented and their effects on university students collaborating with the geopark are examined to set a benchmark for tourism education programs in geoparks in Japan. Students have participated in the programs with the goals of providing suggestions or operations for geotours at Hakone geopark. Educational effects on students, such as interest in the locality, are observed. Students also learn how to work in groups and about their commitments, how to improve the quality of presentations, how to make suggestions for tour planning, how to adjust and negotiate with local suppliers on creating tours, and how to operate tours on site. In particular, students discover the potential of local icons and resources as tourism resources that reflect the characteristics of the area. These educational effects are supported by human and organizational networks in the geopark. Local suppliers and other stakeholders also understand the concept and support activities besides tourism. These networks and an understanding of the geopark and tourism in the locality are the main factors supporting the programs.

著者

新帶 國太郎

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.30, no.3, pp.178-183, 1918-03-15 (Released:2010-10-13)

著者

佐藤 久

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.90, no.4, pp.Plate1-Plate2, 1981-08-25 (Released:2009-11-12)

著者

徳仁 親王

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.123, no.4, pp.389-400, 2014

被引用文献数

3

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.27, no.4, pp.369-369, 1915-04-15 (Released:2010-12-22)

著者

蔵田 延男

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.74, no.6, pp.325-340, 1965

被引用文献数

1

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Since 1946, the exploration used every kinds of prospecting methods to discover groundwater courses in the lava-flows had been practiced on the extensive lower slopes of Mt. Fuji. In this report, the historical explanations and my dearest datum collected extending over past eighteen years are disclosed.<BR>There are several paragraphs, on the geophysical prospecting in large scale derived from the first jointing exploration of 1947, on the adventurous borings to find out the subterranean river in the Mishima lava-flow, on the successful explorations used electric prospecting by the Department of Agriculture and Forestry, on the investigation for Kakitagawa springs as the biggest spring in Japan, on the salt-water encroachment in the artesian aquifer on the southern foot of Mt. Fuji and on the troublesome study to research the hydrogeological connection between the Lake Motosu and the other lakes on the northern foot of the same.

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.50, no.3, pp.142-142, 1938-03-15 (Released:2010-12-22)

著者

汐見 勝彦 松原 誠 小原 一成

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.117, no.1, pp.45-58, 2008-02-25 (Released:2010-02-10)

参考文献数

35

被引用文献数

2 2

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By the end of the last century, the rough configuration of the Moho discontinuity beneath the Japan Islands had been revealed based on explosion surveys and natural earthquake observations. Recently, however, some researchers have pointed out that local roughness of the Moho geometry or relative location between continental and oceanic Moho might provide important knowledge about the source regions of large earthquakes.  Within the southern portion of the Kinki district, the Philippine Sea plate subducts beneath the continental plate at the Nankai Trough. We detect P-to-S converted wave energy from the Moho velocity discontinuity beneath the Kinki district with receiver function analysis, and compare the results of other recent investigations of the depth of Moho. Both oceanic and continental Moho discontinuities are detected in not only our receiver function analysis but also active-source seismic exploration survey and travel-time tomography analysis. The inferred depths of the subducting oceanic Moho beneath the Kii Peninsula, the southern Kinki district, and the continental Moho beneath the northern Kinki correspond well with each other. However, beneath the central Kinki district, no significant converted phases are observed corresponding to the Moho depth inferred from the travel-time analyses. We interpret that no sharp velocity discontinuity exists around the Moho in the central Kinki district.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.17, no.2, pp.153a-154, 1905