著者
湯田 ミノリ 伊藤 悟 内田 均 木津 吉永 伊東 純也
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.117, no.2, pp.341-353, 2008-04-25
参考文献数
21
被引用文献数
2 4

The use of GIS in education in Japan has not yet been widely diffused, although the computer and network environments of schools have been improved, and teachers have already recognized the characteristics and advantages of this tool in education.<br> Nowadays, GIS has been intergraded into many aspects of our lives. Mobile phones are also basic tools in our daily lives. A GIS application that runs on cellular phones would be helpful in school education.<br> From this point of view, the authors have developed a system called Cellular Phone GIS including a GIS application for mobile phone (hereinafter Cell Phone GIS Application) and its web-based GIS viewer application for PC using Google maps (hereinafter PC viewer), and carried out fieldwork at an upper secondary school using these tools. Data can be input and edited outdoors with the Cell Phone GIS Application. These data can be viewed on both cellular phones and personal computers via the Internet. Students carried out a land use survey in the area around the school with the Cell Phone GIS Application, and examined and presented the results using the PC viewer in class.<br> Students participated actively in the fieldwork with the cellular phone. Through experience of the survey with the tool, they found many new things and learned to adopt multi-dimensional points of view and ways of thinking. Also, this project generated more interest among students in geography classes.<br> The Cell Phone GIS Application provided high school students with a feeling of accomplishment from the fieldwork. Meanwhile, this tool and PC viewer minimized work after fieldwork because users do not have to input and aggregate data again. Therefore, teachers and students can use course hours efficiently. The Cellular Phone GIS can provide an environment in which students are able to receive educational effects from fieldwork.
著者
小原 一成
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.112, no.6, pp.837-849, 2003
被引用文献数
5 14

Non-volcanic deep low-frequency tremors detected in southwest Japan are distributed in the forearc side along the strike of the descending Philippine Sea plate. The source depth of the tremor corresponds to the slab interface or the Moho discontinuity. The time sequence of the tremor activity is characterized by long durations from hours to weeks. The mobility and the successive occurrence of the tremor are thought to be related to the existence of fluid liberated from the slab by a dehydration process. The spatial distribution of the tremors is not homogeneous in a narrow belt but is spatially clustered. The major activity of the tremors with relatively long time durations is also clustered periodically, with a period of 2-3 months in the east and middle of Shikoku area and about 6 months in the west of Shikoku. On the other hand, tremors are sometimes triggered by local earthquakes or teleseismic waves. The periodicity of the tremor activity may represent a stable accumulation of fluid with a stable subduction process and the triggering phenomenon implies the unstable condition of the occurrence of tremors.
著者
大石 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.115, no.4, pp.431-447, 2006-08-25
参考文献数
34
被引用文献数
1

After 1969 when the French language became one of Canada's two official languages its sta tus gradually improved. In particular, the Canadian Charter of Freedom and Human Rights, included in the Constitution Act 1982, and the Mah&eacute; case heard by the federal Supreme Court in 1990 as a clarification of the charter promoted improvements to the education system for francophones outside Quebec. In other words, institutional support for francophones has been developed especially in the realm of education. While traditional francophone communities outside Quebec are mostly situated in rural and remote areas, francophone communities have been developed in English-dominant Canadian cities as a result of migration. This study, therefore, attempts to examine language maintenance of francophones and development of their community in the Halifax region, Nova Scotia, as a case of English-dominant Canadian cities, based on the author's field survey carried out in 2003, and which included some interviews.<BR>Concerning the demolinguistic situation in Nova Scotia, an analysis of census data from 1951 to 2001 confirms that the French mother tongue population and the bilingual population in Halifax County increased. In addition, age composition among francophones in Halifax County is much healthier than that of traditional francophone counties.<BR>Most francophones in the Halifax region were born in Quebec or the Maritimes, and moved to the Halifax region to work or enter university, and in some cases, met their future spouses there. Because Halifax is the most important city in Atlantic Canada, many departments and agencies of the federal government have a regional office. Consequently, there are many job opportunities for bilingual people. As a result, it is natural for francophones to work in the Halifax region as bilingual. In 1991, a French school and francophone school board was established in the Halifax region : finally the provincial-wide francophone school board was established in 1996. Of course, education is an important factor for language maintenance. However, the francophones in the Halifax region who want their children to keep the French language not only send their children to a French school in the region, but also make them speak French in conversations with the family members. Much effort is required to keep the French language in English-dominant Canadian cities. However, they succeeded in overcoming these difficulties and developing their community.<BR>Previous studies on language maintenance emphasized institutional support such as education, and its importance is clear in this study. However, institutional support since the 1980s in Nova Scotia seems to be belated in rural and remote areas. On the other hand, the social characteristics of the francophones in the Halifax region make institutional support effective.
著者
片岡 龍峰
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.119, no.3, pp.519-526, 2010-06-25
参考文献数
16
被引用文献数
1 1

&emsp;Possible influences of cosmic rays on terrestrial climate have been studied by many researchers since a good correlation between neutron monitor counts and global cloud amount was reported by Svensmark and Friis-Christensen in 1997. The cosmic ray-cloud relationship may be best tested during Forbush decrease events, in which cosmic rays largely decrease for several days associated with coronal mass ejections. Some cloud parameters are likely to respond to the transient decrease of cosmic rays with a typical time delay of several days, although we do not know the physics behind the cosmic-ray cloud relationship.
著者
宮原 ひろ子
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.119, no.3, pp.510-518, 2010-06-25
参考文献数
20
被引用文献数
1 3

&emsp;The relationship between solar activity and climate change in the past can be examined using proxy records. Variations of solar activity can be reconstructed based on carbon-14 in tree rings, which are produced by galactic cosmic rays modulated by the solar wind, while climate change can be reconstructed from changes of tree-ring growth rate or content of stable isotopes in ice cores from the polar region. A comparison of solar activity and climate change at the Maunder Minimum in the 17<sup>th</sup> century and the Early Medieval Maximum Period in the 9-10<sup>th</sup> century suggests that the sun plays an important role in climate change even on a decadal time scale. The characteristic variations detected in climate change suggest the mechanism of solar influence on climate involves galactic cosmic rays. Variable features of eleven-year and twenty-two year cycles of solar activity and consequent variations of cosmic rays are possible origins of complex variations of climate change on decadal to multi-decadal time scales. We summarize variations of solar activity and cosmic rays during the past 1200 years and their possible influence on climate change.
著者
山岡 耕春 中禮 正明 安藤 雅孝
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.2, pp.185-191, 2002-04-25
参考文献数
9
被引用文献数
2

The temporal relationship between the interplate and inland earthquakes of Kyushu Island region was investigated. We analyzed this relationship by stacking the temporal frequency of the inland earthquakes with reference to the occurrence time of each major interplate earthquake in the Hyuga-nada region, that occurred between 1900 and 2000. A good coincidence of occurrence between the inland and the interplate earthquakes is recognized. While the tendency of the occurrence after the interplate events has already been pointed out, we found that the inland earthquakes also tend to occur before the interplate events. Abrupt activation of the inland earthquakes within several months before major interplate earthquakes is recognized in addition to the tendency to occurr afterwards. The preceding inland earthquakes may indicate that they are triggered by precursory slow slips around the hypocenters of the Hyuga-nada earthquakes.
著者
渡辺 光
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.1, pp.1-7, 1952
被引用文献数
2

This article presents a basis for the subdivision of Japan into landform divisions, and to proceed to give the names and locations of the divisions. The fundamental premise in determining landform divisions is a fact that Japan is a single structural and geomorphologic unit from the world or the continental viewpoint, and the whole country is included in the Circum-Pacific Orogenic Zone. Therefore, the orogenc processes that have had much to do in forming the major landforrn features are considered to be the fundamental basis for determining the primary landform units.<BR>The following four primary landform divisions or Regions are differentiated by essential difference in recent orogenic movements, landform features, structures and means of coalescence of those arcs. They are ; A) Hokkaido Proper Region B) Northeast Region C) Central Region D) Southwest Region. The latter three regions are each composed of two or more subregions which coincide with the major tectonic units. Each traditional tectonic unit is taken as an independent subregion. These regions and subregions in turn are divided into districts on the basis of the differing effects of endogenic processes such as natures and amount of earth movements or volcanic activities. The districts are again divided into Sections en the basis of minor landform features resulting from either endogenic or exogenic processes. According to the above items, four regions, eight subregions, 51 districts and 240 sections have been established.
著者
渡辺 光
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.69, no.4, pp.145-152, 1960
被引用文献数
1

As premises for main topics of inquiries, a brief review is made of the status of the wartime geography in Japan which should seem to have a direct bearing on the later development of this field. There, the oversea expeditions, war-time researches, and &ldquo;Geopolitik&rdquo; at their time, and their later influences are pointed out.<BR>Status of Geography since 1945 is elucidated according to the following headings.<BR>1) Various kinds of national land surveys in connection with the various land planning projects.<BR>2) Promotion of international intercourse.<BR>3) Establishment of departments of geography in universities and colleges throughout the country.<BR>4) Dispatch of oversea scientific investigation parties.<BR>5) Propulsion of joint studies by workers of various fields of geography, and participation of geographers in various interdisciplinal studies.<BR>6) Problems waiting for future solution.
著者
舟田 久之
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.101, no.6, pp.491-505, 1992-12-05
参考文献数
18
被引用文献数
1 1
著者
田中 圭 中田 高 松浦 律子 田力 正好 松田 時彦
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.127, no.3, pp.305-323, 2018
被引用文献数
1

<p> <i>Kambara Jishinyama</i> (earthquake-mound) located on the west bank of lower reach of the Fujikawa river, is widely believed to be a mound that was tectonically formed at the time of the 1854 Ansei Tokai earthquake. Using old maps and aerial photogtaphs, geomorphological changes around <i>Kambara Jishinyama</i> before and after the earthquake are examined. The Fujikawa river frequently flooded and the course on its west bank changed especially after construction of the <i>Karigane-zutsumi</i> (big bank) in order to protect farmland on its east bank. The area around the lower reach of the river was surveyed in 1803 for the <i>Dai Nihon Enkai Yochizu</i> large-scale map, which is the so-called <i>Ino-Daizu</i>. On that map, the river was at almost the same location as its present course. The historical road map (<i>Kaido-Ezu</i>) of <i>Tokaido</i>, which was the trunk road connecting Edo and Kyoto, illustrated in the same period as <i>Ino-Daizu</i>, shows that the Fujikawa river shifted its course close to the foot of river terraces at the west bank. Due to lateral erosion of the river, part of the <i>Tokaido</i> between the towns of Iwabuchi and Kambara collapsed several times. Subsequently, the road was diverted to the new route via Shinzaka as shown on the 1:20,000 scale topographic map published in 1890. A micro-landform classification map of the alluvial lowland of the west bank of the Fujikawa river based on interpretations of aerial photographs taken in 1952 and 1953 reveals that <i>Kambara Jishinyama</i> was located on one of the former mid-channel bars in the braided channels of the river before the 1854 Ansei Tokai earthquake. The earthquake caused a large landslide that dammed the Fujikawa river for a short period at the foot of Shiratori-yama to the north of Iwabuchi. The discharged flood water changed the river course close to the present stream. Geomorphic evidence for tectonic uplift does not exist around <i>Kambara Jishinyama</i>. The Koike river, a small stream flowing in the former main stream of the Fujikawa river, abandoned at the time of the Ansei Tokai earthquake, concordantly flows into the present main stream of the Fujikawa river showing that co-seismic uplift did not take place at the west bank. We conclude that <i>Kambara Jishinyama</i> was not tectonically formed by the earthquake, but is a product of the river course change.</p>
著者
久野 久
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.73, no.5, pp.279-280, 1964
被引用文献数
1

Basalt magmas in Japan range in composition from tholeiite, passing through high-alumina basalt, to alkali basalt. Picrite basalt related to either of these three basalt magmas is scarcely represented. In Hawaii, both tholeiite and alkali basalt are closely associated with picrite basalt having bulk compositions intermediate between the ordinary basalt and peridotite. The Japanese basalt magmas are supposed to be produced by sudden release of stress attending the generation of the intermediate to deep-focus earthquakes. In such a case, there may be a certain limitation of the heat energy supply for melting the mantle peridotite ; only a few per cent of the peridotite would be melted to form the basalt magmas.<BR>The Hawaiian basalt magmas are supposed to be produced by the heat transfer due to convection current within the mantle. In such a case, there would be less limitation of the heat energy supply for melting ; a greater per cent of the peridotite would be melted, resulting in the production of picrite basalt magmas.
著者
新谷 俊一 田中 和広
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.118, no.3, pp.340-349, 2009-07-07
参考文献数
20
被引用文献数
3 12

&emsp;Mud volcanoes are structures formed as a result of the emissions on a land surface or the sea floor of argillaceous material, which is composed of erupting remobilized mud, petroliferous or magmatic gases, and high-salinity water. Recently, large constructions have been planned deep underground besed on the expectation of geological stability. Therefore, it is important to study the origin of erupted mud and groundwater and the depths from which they ascend when evaluating long-term stability. Three active mud volcanoes and a passive mud volcano are found in the Tertiary Shiiya Formation distributed in Tokamachi City, southern part of Niigata Prefecture. Detailed descriptions of the mud volcanoes are provided by Shinya and Tanaka (2005). However, the origin of erupted mud and the formation mechanism of abnormal pore water pressure have not yet been identified. The authors measured the oxygen and hydrogen isotopic ratio of groundwater and vitrinite reflectance of coal fragments separated from erupted mud of an active mud volcano to investigate the origin of erupted mud, particularly the depth of the origin, and the formation mechanism of abnormal pore water pressure. As a result, &delta;<sup>18</sup>O and &delta;D values of erupted water are 1.2&permil;, -5&permil; respectively, showing good agreement with those of the Nanatani Formation distributed at a depth of 3400 m in depth in the studied area. Vitrinite reflectance (Ro) shows a bimodal distribution (<i>i.e.</i>, 0.3-1.2% and 1.5-1.8%). Ro value of coal fragments sampled from the Shiiya Formation at the outcrop in the studied area are 0.3-0.45%. High Ro (1.5-1.8%) values of coal fragments are obtained in core samples at a depth of 4000 m in the Gimyo SK-1 oil well, which was excavated 2 km NW from the mud volcano. As a result of an investigation of erupted materials at the mud volcano, they were found to have originated at depths of from 3400 m to 4000 m in the studied area. Geothermal temperature of underground at depth of 3400 m to 4000 m in the in the studied area is estimated to be about 120&deg;C to 150&deg;C. Estimated temperature is high enough to cause diagenetic transition from smectite to illite. Transition from smectite to illite results in the release of a large volume of pore water into the sediment. It is concluded that dehydration due to mineral transition might be the major reason for abnormal pore water pressure formation at depths of 3500 m to 4000 m in the study area.