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

Mori Jim 加納 靖之

出版者

Tokyo Geographical Society

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.118, no.3, pp.492-498, 2009-07-07

参考文献数

16

被引用文献数

1 9

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2006年5月26日に発生したジョグジャカルタ地震による地震動が,250km離れたインドネシアのSidoarjo泥火山の噴出を誘発した可能性について検討した。この泥火山は2006年5月から噴出を続けている。泥火山の近傍で生じた流体圧変化と地震発生の時間的な一致から,地震波がこの地域の地下流体の状態に影響を与えたことが示唆される。別の同規模の地震のデータを用いて,地震波による応力変化の大きさを見積った。応力変化はごくわずか(0.005から0.010MPa)であったが,他の地域であればこの程度の応力変化でも微小地震を誘発した場合がある。地震の数分後に流体圧変化が生じたようであり,これは地下流体が地震動に対して応答したことを示していると考えられる。2006年ジョグジャカルタ地震は,Sidoarjo泥火山で小さな流体圧変化をひきおこした可能性があるが,これが泥火山の噴出開始に直接関係しているかどうか評価することは困難である。

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

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.2, no.12, pp.654a-654a, 1890

著者

苅谷 愛彦 高岡 貞夫 佐藤 剛

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.768-790, 2013-08-25 (Released:2013-09-11)

参考文献数

63

被引用文献数

12 13

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We studied the geomorphological and geological characteristics of four medium- to large-scale landslides that occurred in the alpine and subalpine zones of the northern Japanese Alps and assessed the relationship between landslide features and vegetation diversity in the landslide areas. To achieve this, we conducted field investigation and laboratory work including airphoto interpretation and radiometric dating of soils and fossil logs. Our field investigations indicate that, even in alpine and subalpine zones, landslide blocks (i.e., landslide deposition areas) display specific landforms such as scarplets, shallow depressions, and low mounds with linear or curved forms. Vegetation cover and aquatic areas such as peat bogs and moors also display linear or curved patterns that are superimposed on these small topographic features. We found that the highly diverse landscapes in landslide blocks were substantially different from those in present-day or fossil periglacial slopes near the main ridges, both of which displayed monotonous facies. The specific patterns of vegetation cover seen on landslide blocks probably formed under the influence of different slope environments, with variations of parameters such as inclination, soil properties, thermal-water regimes, and microclimate occurring as a result of landslide activities. Similarly, geomorphic changes such as channel migration and waterfall formation in and around areas of landsliding probably affected biological evolution and differentiation, and resulted in multiple modulations of the gene expression of aquatic organisms. Medium- to large-scale landslides are often reactivated by secondary movement. We suggest that subsequent variations of the landforms in the landslide blocks caused sudden or gradual changes in the surrounding natural environments, which had been forming since the initial mass movement. The biota present in a landslide block is the result of evolution and differentiation during geomorphic changes such as those described here; therefore, it is possible that secondary landsliding resulted in increased biological diversity and complexity.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.41, no.2, pp.122a-123, 1929

著者

猪間 收三郎

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.52, no.7, pp.337-341, 1940-07-15 (Released:2010-10-13)

著者

松井 圭介

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.451-471, 2014

被引用文献数

4

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The distribution and landscape of temples and shrines and their functions in the City of Edo are examined, and urban structures constructed based on mystical and religious aspects of spatial design are evaluated.<br> The five key findings of this study are:<br> 1. A city design modeled on <i>Heiankyou</i> (ancient Kyoto) was applied to the construction of the City of Edo, and was arranged according to four directions and their connections with gods. This model was meant to protect the City of Edo not only militarily, but also in magical and religious ways. In particular, large temples and <i>chinju-sha</i> shrines, which were strongly associated with the Tokugawa shogunate family, were placed to face northeast/southwest—directions regarded as being unlucky—as well as towards places of execution and the locations of red-light districts in areas bordering the city. This placement created an extraordinary atmosphere in the city. Tokugawa Ieyasu was awarded a posthumous <i>shingo</i> (literally, a Shinto deity) title, "Tosho Daigongen," and was enshrined angled towards the North Star (i.e. <i>Nikko</i>) to protect the City of Edo. The attempt to harness these magical factors to protect and safeguard the City of Edo is one of its characteristics.<br> 2. Temples and shrines were under the control of the Tokugawa shogunate during the Edo Period, and the <i>Honmatsu-seido</i> (government-enforced main-branch temple system) was established through the enactment of <i>jiinhatto</i> (laws for temples). In addition, members of the public were forcibly linked to temples and shrines through their status as <i>danka</i> (temple supporters) under the <i>Terauke seido</i> (a system that compelled the public to become Buddhists). Through this administration of religion, temples were integrated into a system for maintaining social order as a marginal role in the mechanism of the Tokugawa shogunate.<br> 3. The temple and shrine estates as a whole were almost the same size as the space allocated for the townspeople, and occupied a large proportion of the City of Edo in terms of land use. Shrines increased rapidly in number as the city's population increased. As a result, control measures were introduced to restrict the establishment of temples in the city's central area, where strong demand had led to a severe land shortage, and these temples were instead almost forcibly moved to the suburbs. This tendency became more evident in city planning after the Great Fire of Meireki in 1657; subsequently, new "towns of temples" were created in districts such as Asakusa, Shitata, and Mita.<br> 4. The rapid expansion of urban areas in the City of Edo led to religious facilities using their precincts as places to lease land and rent houses. As a result, new <i>monzen-machi</i> (temple towns) were created within the precincts of large temples, and some of these towns developed into entertainment districts, housing performing arts and drama facilities.<br>(View PDF for the rest of the abstract.)

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.21, no.1, pp.69a-69a, 1909

著者

中村 洋一 ハリー グリッケン

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.97, no.4, pp.309-316, 1988-08-25 (Released:2011-02-17)

参考文献数

24

被引用文献数

4 9

著者

伯野 元彦

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.115, no.4, pp.466-469, 2006-08-25 (Released:2009-11-12)

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Recent earthquake damage in Japan has the following features. 1) Damage is not proportional to the recorded acceleration of earthquake. 2) Damage on the soft ground is severer. 3) Most of damage comes from the collapse of old wooden houses. 4) 40% of fires after earthquake are related to electricity.

著者

鈴木 毅彦

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.2, pp.182-197, 1990-04-25 (Released:2009-11-12)

参考文献数

35

被引用文献数

6 6

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Akagi volcano situated in the North Kanto district of central Japan is a Quaternary volcano. The eruptive history of this volcano during the last 200, 000 years is clarified by the tephrochronological study.The plinian pumice fall deposits derived from Akagi volcano are as follows in ascending order; the Moka Pumice (MoP), Akagi-Mizunuma Pumice-16. …-12, -10…-1 (MzP-16…-12, -10…-1), Namekawa Pumice-2, -1 (Nm-2, -1), Yunokuchi Pumice (UP) and Kanuma Pumice (KP) (Fig. 1). Stratigraphy, distributions and petrographic characteristics of these tephras are described (Figs. 5, 6, 8, 9 and Tables 1, 3).The MoP pumice fall deposit covering the most part of the eastern part of the North Kanto district, erupted in the penultimate glacial stage preceding the Last Interglacial Stage. Moreover, the stratigraphic relations of the MzP-10…-1, Nm-2, -1 and UP with the well dated widespread tephras, which are the K1P-7 (ca. 130 ka), DPm, On-Pm I (ca. 80 ka), K-Tz (ca. 75-80 ka), Aso-4 (ca.. 70 ka) and DKP (ca. 45-48 ka), are clarified (Fig. 7). These data can give the chronological framework for the eruptive history.The MzP series, Nm-2, Nm-1 and UP erupted during the stage called the younger stratovolcano (YS) of the Akagi volcano in previous work (Fig. 10). The total volume of the plinian pumice fall deposits from the MzP-10 to the UP amounts to 28 km3. This corresponds to the discharge rate of the pumice equivalent to 0.33 km3/1, 000 years and the frequency of the plinian eruption 0.15/1, 000 years.Before the formation of the central cone, it occurred the most eruptive episode of Akagi volcano. This is represented by the members : the KP pumice fall deposit (ca. 31-32 ka) and the Mizunuma lithic (chert lapilli) fall deposit (CLP). The volume of the KP deposit which amounts to 25 km3, is the largest volume of the plinian pumice fall deposits derived from Akagi volcano.

著者

小泉 尚嗣

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

pp.2012ap03, (Released:2012-12-05)

参考文献数

62

被引用文献数

7 6

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Research on coseismic and postseismic groundwater pressure changes is important for evaluating long-term groundwater stability in seismically active regions such as Japan. It is also important for preventing and reducing earthquake-induced geological disasters such as landslides. This study reviews literature and clarifies abrupt coseismic changes and subsequent postseismic gradual changes in groundwater pressure. Coseismic changes result from ground shaking and coseismic crustal deformation. Postseismic changes are gradual changes, which can be described by a diffusion equation with new initial values and boundary conditions due to ground shaking and coseismic crustal deformation. The effects of crustal deformation on groundwater pressure appear to be limited in the vicinity of the seismic source region, although that of ground shaking can remain in distant areas. Because a variety of factors and conditions affect earthquake-related groundwater pressure changes, each should be investigated to more accurately clarify the effects on coseismic and postseismic groundwater pressure changes. This research may contribute toward clarifying seismicity mechanisms triggered by distant earthquakes.

著者

三野 與吉

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.43, no.5, pp.256-267, 1931

被引用文献数

1

著者

小泉 武栄

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.761-774, 2011-10-25 (Released:2012-01-17)

参考文献数

20

被引用文献数

4 6 6

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A geopark involves not only a geological heritage but also geographical and ecological elements. Therefore, subjects related to geotourism are not only landforms and geology, but also ecosystems, including vegetation and animal communities, and human landscapes, such as terraced rice paddies and grasslands created by human activity. Because geotourism covers a broad range of elements, from geo- and ecosystems to human activities, it is expected that the further development of related activities will be supported and approved by an increasing number of people. In this manuscript, I introduce some examples of geo-ecotourism as a special type of geotourism, including: vegetation at the summit area of Mount Hakusan, vegetation in a landslide scar on Mount Bandaisan, and the habitat of Dicentra peregrine on Mount Yatsugatake. These were all very popular with the participants of excursions I conducted. Geotours also promote regional development because they benefit residents economically by employing local workers and travel-related businesses, and encourage consumption of local services and products by visitors. A pressing issue concerning geotourism in Japan is the development of human resources such as tour guides. A geotour needs an excellent guide with a riveting interpretation. There are, however, few of such guides and there is a need to rapidly foster more. As a model for fostering guides, I introduce my “Intensive course on the natural history of mountains,” which interprets the natural history of mountains based on geo-ecology. In the long term, however, it is necessary to introduce natural history education into the school system and improve the quality of nature programs broadcast on TV. Many participants of geotours are middle aged and older, and tend to be energetic and slow to age. This may be because the tour participants are required to do physical activity and to use their common sense. Based on this perspective, a geopark approach must gain in importance within social and lifelong education.

著者

角田 寿喜 後藤 和彦 宮町 宏樹 平野 舟一郎 清水 力 岩切 一宏 中辻 剛 立山 清二

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.4, pp.476-485, 1997-08-25 (Released:2009-11-12)

参考文献数

26

被引用文献数

1

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A shallow earthquake of MJMA 6.7 on October 18, 1995, at about 50km southeast off Kikai-jima in the Ryukyu Islands caused slope landslides, subsidence of concrete slabs at fishing ports and collapses of walls piled up with coral ragged stones. Several fishing boats moored to wharves were damaged by tsunami; four boats were turned over at ports in Amami-Oshima.From May 19 to 30, 1995, earthquakes of MJMA≤4.1 had occurred in the focal area after a long seismic quiescence since the 1911 Kikai-jima Earthquake of M=8.0. Some of them were felt in JMA intensity 1 or 2 at Kikai-jima. Numerous felt shocks also struck the island immediately after the main shock; 62 and 125 shocks on October 18 and 19, respectively. Numbers of aftershocks decreased rapidly, though they lasted through the end of 1996.The damage distribution of the 1911 event being compared with that of the 1995 event, their focal areas were considered to overlap with each other. It was, however, possibly an interplate earthquake of a thrust fault type in contrast with the 1995 event of a normal fault type in the subducting plate, because the first motions of P wave at Naze and of tsunami wave at Kikai-jima were reversed between the two events.

著者

宇佐美 龍夫

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.94, no.7, pp.656-664, 1986-01-25 (Released:2009-11-12)

参考文献数

6