著者

山田 直利 矢島 道子

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.125, no.2, pp.257-267, 2016-04-25 (Released:2016-05-12)

参考文献数

9

---

Edmund Naumann (1854–1927), the first professor of the Geological Institute, Science Department, the University of Tokyo, presented a proposal to found the Geological Survey of Japan to Hirobumi Ito, Minister of the Home Affairs of Japan, in 1879. The Japanese Government immediately accepted this proposal, so Naumann resigned his post as a professor of the university and returned to Germany, in order to find the necessary specialists and items for the upcoming survey. During his stay in Germany, on January 3rd, 1880 he gave an invitation lecture on Japan, which was published in “die geologische Verhandlungen der Gesellschaft für Erdkunde zu Berlin” as a paper titled “Ueber die wirthschaftlichen Verhältnisse Japans und die geologische Aufnahme des Landes” (The economic situation of Japan and the Geological Survey of Japan). This paper introduced the feudal system, which had controlled Japan through the Middle to Modern ages, the economic situation of Japan after the Meiji Restoration, especially for agriculture, means to promote Japanese agriculture and industry, and the purpose and tasks of the Geological Survey of Japan. The paper, which we have now translated into Japanese, is important because it is similar to the Japanese translation of the above proposal handwritten in 1879, and the original text of the proposal, probably written in German, has now been lost.

著者

日下部 四郎太

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.18, no.6, pp.393-403, 1906-06-15 (Released:2010-10-13)

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^th century and the Early Medieval Maximum Period in the 9-10^th 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

湯田 ミノリ 伊藤 悟 内田 均 木津 吉永 伊東 純也

出版者

東京地学協会 = Tokyo Geographical Society

雑誌

地學雜誌 = Journal of geography (ISSN:0022135X)

巻号頁・発行日

vol.117, no.2, pp.341-353, 2008-01-01

被引用文献数

4

---

金沢大学人間社会研究域人間科学系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.  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.  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.  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.  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

前野 紀一

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.98, no.6, pp.761-767, 1989-12-05 (Released:2009-11-12)

参考文献数

22

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

馬場 知哉 柿澤 茂行 森 宙史 車 兪澈 黒川 顕 大島 拓

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.6, pp.805-824, 2020-12-25 (Released:2021-01-18)

参考文献数

103

被引用文献数

3

---

Estimating the “minimal gene set” for a cell to be viable is an important issue in understanding “living” cells, creating “artificial” cells, and revealing “ancient” cells. The minimal gene set is critical information for understanding a cell system and designing an artificial genome, which is an essential element for creating an artificial cell. Artificial cells can provide many clues to understanding primordial life on Earth. To reveal minimal gene sets, “essential genes” in many bacteria, which could not be removed from bacterial genomes, have been identified. Bacteria are the most useful organisms for identifying essential genes from their specific characteristics: small genomes, rapid growth, and species that are easy to manipulate genetically. Therefore, various investigations on minimal gene sets or minimal genome of bacteria are reviewed, and “the minimal gene set for a viable cell” is discussed.

著者

萩原 幸男

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.99, no.1, pp.72-80, 1990-02-25 (Released:2010-11-18)

参考文献数

13

被引用文献数

2

---

The Itoigawa-Shizuoka Tectonic Line (ISTL) forms the western margin of the Fossa Magna separating the Northeast Japan from the Southwest Japan. The conventional idea insists that both the Northeast Japan and the Southwest Japan belong to the Eurasian plate (EUR). A hypothesis has recently proposed, however, that the Northeast Japan belongs to the North-American plate (NAM), while the Southwest Japan belongs to EUR. If we approve the hypothesis, it follows that ISTL is a plate boundary between these two plates. The purpose of this paper is to define ISTL as a kind of plate collision boundaries on the basis of gravity data.ISTL runs across a positive Bouguer anomaly belt with the width of about 30km located on the Japan-Sea coast. The Bouguer anomaly there is about 30 mgal higher in the west side of ISTL than in the east side. This implies that, if we assume ISTL to be a plate subduction boundary, the eastern plate sinks down the western one along ISTL. On the other hand, the inland part of ISTL between Omachi and Matsumoto cities is characterized by a large NS-trending thrust called “East Matsumoto Basin Fault”, the west side of which subsides down the east side. The existence of this thrust is confirmed by both gravity and explosion seismic data. The movement of this thrust is evidently opposite to the plate sinking on the Japan-Sea coast.ISTL turns its way to the NW-SE direction at the south end of the East Matsumoto Basin Fault. The left-lateral slip is predominant from Suwa to Kofu cities, and its horizontal displacement amounts to about 12 km long from geological considerations. The leftlateral movement there can be interpreted from a crustal compression in the EW direction which is caused by a plate collision. The graben lies along this part of ISTL. We find a gravity difference amounting to 20-30 mgal at its maximum between the inside and the outside of the graben. Assuming that a density contrast of basement with sediment buried in the graben is 0.5g/cm3, we estimate the vertical displacement of the graben wall as 1-1.4 km. Our estimation is consistent with the fact that a 800m deep drilling does not reach the basement in the Suwa basin.If we approve the previously mentioned hypothesis, the Kofu basin is considered to be a tripple junction of three plates: EUR, NAM and the Philippine-Sea plate (PHS). Accordingly, the southernmost part of ISTL is a subduction boundary of PHS sinking down EUR, extending southward to the Suruga trough in the Pacific Ocean. Meanwhile, the NAM-PHS boundary runs southwestward from the Kofu basin to the Sagami trough. The highpass-filtered Bouguer anomaly on the inland part of PHS intensifies NE-SW trending short-wavelength undulations of gravity field, which may reflect the northeastward movement of PHS.Geoscientific investigations can not define the Northeast Japan as a part of NAM, but find sufficient evidence for the fact that ISTL is a collision boundary between EUR and the other continental plate except for the PHS area. The gravity data also support this conclusion.

著者

下司 信夫

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.127, no.2, pp.175-189, 2018-04-25 (Released:2018-06-11)

参考文献数

47

被引用文献数

2 2

---

The fundamental structure of a collapse caldera is subsidence of a block(s) into a magma chamber with the evacuation of a massive volume of magma from the chamber. Decompression of a magma chamber caused by the extraction of magma from a magma chamber coinciding with pyroclastic eruption, effusive eruption, and lateral magma migration drives caldera collapse. Caldera-forming eruptions exhibit wide variations. Caldera-forming pyroclastic eruptions are characterized by a high eruption rate, whereas caldera-forming effusive eruptions have a much lower effusion rate. Caldera collapse caused by a pyroclastic eruption generally occurs within one day, whereas incremental collapses continue for up to one month in the case of some effusive eruptions. Collapse calderas also have wide structural variations. The aspect ratio of the roof of the magma chamber controls the development of caldera faults. The development of multiple caldera faults with a high aspect ratio causes piecemeal collapses, whereas a low aspect ratio results in the subsidence of coherent blocks detached by a simple ring fault. With the progress of caldera subsidence, the caldera structure develops from a flexural down sag to a double-ring fault system, and finally reaches an upward-flaring “funnel shaped” caldera following an intense collapse of the caldera wall. Calderas vary widely in size from 1 km to 100 km, and can also be divided into at least three classes by their internal structures. The largest group of more than 20 km across is characterized by flexural down-sag deformation. The intermediate-size group is characterized by well-developed caldera-border faults. The smallest calderas of less than 10 km across may have piecemeal structures. The existence of a pre-caldera volcanic edifice is also an indicator of differences in the magmatic system. Some calderas form at the summit of a pre-existing stratovolcano or shield volcano, whereas some large calderas form in a cluster of small volcanoes, involving non-volcanic basement rocks. A structural model of caldera development should involve these wide spectrums of collapse calderas. The development of collapse calderas is controlled by variations of magmatic activity, such as eruption style, eruption rate, and duration of eruption, as well as the architectures of their magma storage systems.

著者

野坂 俊夫

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.117, no.1, pp.253-267, 2008-02-25 (Released:2010-02-10)

参考文献数

51

被引用文献数

2 2

---

Gabbroic rocks recovered from deep holes in the oceanic crust significantly vary in the abundance and assemblage of alteration minerals, showing a close association with the original lithology and distribution of dikes and veins. The mineralogical variation is considered to reflect the durability of primary minerals, accessibility and composition of alteration fluids, and alteration temperature. Textural relationships of alteration minerals suggest a common cooling history of oceanic gabbros from granulite or pyroxene hornfels facies to zeolite facies conditions. It is considered that regardless of spreading rate, the static formation of upper greenschist- to lower amphibolite-facies minerals is the dominant alteration process at the lower crust near oceanic ridges, whereas subgreenschist-facies alteration represents the exhumation histories of gabbroic masses from depth. High-temperature plastic shear zones with almost anhydrous recrystallization of primary minerals develop locally at slow-spreading ridges, and possibly provide pathways for later hydrothermal fluids. In contrast to the gabbroic rocks, oceanic peridotites have a monotonous mineralogy formed during low-temperature serpentinization processes, making it difficult for us to depict their cooling histories or in-situ alteration processes at the upper mantle. The hypothesis that oceanic Moho represents a serpentinization front in peridotites is suitable for the uniformity of crustal thickness inferred from seismological observations, but lacks a rationale for supplying a constant amount of water to the upper mantle or for the cessation of serpentinization at a constant degree. Alternatively, preferential alteration of pyroxene at relatively high-temperature conditions might form the oceanic crust of uniform thickness.

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

小林 貞一

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.56, no.5, pp.151-185, 1944-05-15 (Released:2010-10-13)

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.13, no.4, pp.244a-246, 1901

著者

保柳 睦美 内藤 誉三郎 和達 清夫 伏見 康治 矢澤 大二

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.89, no.1, pp.71-77, 1980

著者

和達 清夫 荒川 秀俊

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.63, no.3, pp.117-121, 1954

著者

和達 清夫

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.100, no.1, pp.1-2, 1991-02-25