著者

柴田 賢

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.94, no.7, pp.682-686, 1986-01-25 (Released:2009-11-12)

参考文献数

10

著者

David Simon

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.65, no.2, pp.100-105, 1956-06-30 (Released:2009-11-12)

参考文献数

1

---

ソヴィエットの樺太および千島列島占領は, 以前の日本語の地名のあらゆる痕跡を拭い去つてしまつた。こんにちでは, 日本語の影響をほのめかす地名は, 一つとて存在しない。残されている地名はたゞアイズ語に起源をもつ, 若干のものであり, それらでさえも, ロシア当局によつて, 入念に篩にかけられた。ここに挙げたものは日本語の照合名, 地理的経緯度および地名起源の簡単な説明を加えた, 100の選択されたロシア語の地名である。

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

池原 研

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.110, no.4, pp.471-478, 2001-08-25 (Released:2009-11-12)

参考文献数

23

被引用文献数

12 14

---

Deep-sea turbidite has potential for paleoseismicity analysis. Many deep-sea turbidites were intercalated in two sediment cores collected from two slope basins off Tokai area along the eastern Nankai Trough. Geological and topographic setting of the basins suggests that these turbidites were of earthquake origin. Depositional age of each turbidite layer was determined by radiocarbon dating using planktonic foraminifera in hemipelagic mud. The results indicated that large earthquakes along the eastern Nankai Trough might have occur periodically every 100-150 years during the last 3000 years.

著者

宮本 真二

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.107, no.4, pp.535-541, 1998-08-25 (Released:2014-02-26)

著者

野間 三郎 門村 浩 中村 和郎 野沢 秀樹 堀 信行

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.83, no.2, pp.103-124, 1974-04-25 (Released:2010-02-25)

参考文献数

157

著者

野間 三郎 門村 浩 中村 和郎 野沢 秀樹 堀 信行

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.83, no.1, pp.19-37, 1974-02-25 (Released:2009-11-12)

被引用文献数

1

著者

奈須 紀幸

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.102, no.6, pp.645-663, 1993-12-05 (Released:2010-11-18)

参考文献数

19

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

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

小山 真人

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.103, no.5, pp.576-590, 1994-10-25 (Released:2009-11-12)

参考文献数

56

被引用文献数

4 7

---

Izu Peninsula and adjacent areas, which are located on the northern tip of the Izu-Bonin volcanic arc, are characterized by intense crustal movements and volcanic activity. Many geomorphological, geological, and geophysical data were collected from this area and various tectonic models were proposed to explain them systematically. These tectonic models can be classified into two categories : models 1 and 2. While model 1 regards the area as a single tectonic province, model 2 proposes two or more tectonic provinces, which are bounded by tectonic lines. Models 1 and 2 can be classified into models 1A and 1B, models 2A, 2B, 2C, and 2D, respectively. Model 1A hypothesizes an anticlinal bend of the Philippine Sea plate, which is being generated by the subductions along the Suruga and Sagami troughs. Model 1B emphasizes the crustal stress field generated by the collision of the Izu-Bonin volcanic arc with Japan arc and the slab-pull force along the Sagami trough. Since there are many local tectonic features that cannot be explained by model 1A or 1B, models 2A-2D were proposed. Model 2A divides the study area into two tectonic provinces : the northern province of compressive deformation by conjugate faults and the southern province of right-lateral shearing deformation. Model 2B divides the area into the eastern and western provinces, which are defined by sharp contrasts in the geologic structure, seismicity, crustal stress field, crustal movements, focal mechanisms of earthquakes, paleomagnetic directions, and volcanic activity. Many observations support the validity of the model 2B tectonic provinces. Model 2C introduces the hypothesis that the Izu-Bonin arc is being fractured into the inner and outer arcs because of a contrast in buoyancy. The existence of the estimated model 2C fracture, W est Sagami Bay Fracture, is still under debate. Model 2D regards the Higashi-Izu monogenetic volcano field, located in the eastern Izu Peninsula, as a field of crustal spreading. Model 2D proposes a key to understanding a sharp contrast in tectonic features between the eastern and western provinces of model 2B as well as the complex geometry of the Philippine Sea slab beneath the Japan arc.

著者

横山 祐典

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.111, no.6, pp.883-899, 2002-12-25 (Released:2009-11-12)

参考文献数

62

被引用文献数

9 7

---

Global ice volume during the last glacial stage was obtained using geological observations from the sites located away from the former glaciated regions. The advantage using such records is that the area has been less influenced from the readjustments of the crust due to glacial isostasy. However the effect is still not negligible in those areas and hence it is required to correct sea-level records for both glacio-and hydro-isostatic effect to extract past global ice volume information. The record shows progressive growth of global ice volume since the end of the Last Interglacial. Rapid fluctuations of the volume were also observed during the last ice age corresponding to the Heinrich events observed in the North Atlantic ocean as well as Dansgaard-Oschgar events seen in the Greenland Ice cores. The Last Glacial Maximum was ranged between 30, 000 years ago to 19, 000 years ago and ended by the rapid disintegration of the ice volume that corresponding to decrease of the ca. 10 m of ice-volume equivalent sea-level. Gradual sea-level rise was seen during the late glacial stage, except the time known as melt-water pulse la in the Barbados coral, but other catastrophic rises were not found in the records. Main phase of deglaciation was ended until ca. 7000 years ago, yet slight decrease in ice volume equivalent to the 3 m global sea-level has been occurred since then. Sea-level change namely global ice volume fluctuations had been played as major role for human migration from Africa to the other parts of the world during the last ice age. Therefore studies on coastline changes will provide an useful information for the research on spatial and temporal histories of past human life styles.

著者

森本 良平 小坂 丈予 羽鳥 徳太郎 井筒屋 貞勝 浦部 和順 高橋 春男 岡田 義光 平林 順一 伊佐 喬三 磯部 宏

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.77, no.5, pp.255-283, 1968-10-25 (Released:2009-11-12)

参考文献数

25

被引用文献数

3 3

---

Unusual uplift of the land was found about an insular active volcano Iwo-jima, Ogasawara archipelago, 1, 200 km south of Tokyo. Remarkable retreat of shore line was revealed by reviewing topographic maps and aerophotographs of the island. Some upward movements of the island are to be one of the most principal reasons of the retreat. As the clear evidences of the upheaval of the land, following phenomena were observed by the writers who investigated the island five times from 4th July to 23rd August 1968 : a) Sunken vessels and a landing craft have emerged on the western coastal beach of the island : b) Faults and cracks appeared on the abandoned run-way of the former Japanese Navy in the central part of the island ; c) Coastal reef emerged on the sea to connect off shore islet with the island ; d) New coastal terraces were formed on the sand beaches ; e) Fresh living corals were exposed on the sea.Results of the investigations are enumerated as follows : 1) About 8 m upheaval of the land since 1953-4 was revealed by levelling survey at the western coast of the island. 2) Amount of uplift observed on the above-mentioned run-way is smaller in its central part than in both terminals, maximum vertical displacement of the fault being 3 m. 3) Tide gauge installed at the western rocky coastrecorded slight relative down of sea level but further observation should be continued without disturbance by typhoon to obtain more reliable data. 4) No expected microseisms were recorded on the high sensitive electro-magnetic seismographs except 2 or 3 per day. 5) Temperature of the fumarolic gases were 95-123°C, 10-25°C higher than that observed in 1935. In spite of the rise in temperature, gases of so called high temperature type, such as sulphur dioxide and halogens, were not contained. 6) Composition of the sublimates also accords with these results of chemical analyses of the gases. 7) Content of each main component element and its ratio to other ones is quite variable in several hot springs whose pH values range from 2.1 to 6.8. 8) Analcite was identified by X-ray and DTA analyses in the tuff forming Moto-yama, an eastern main flat cone of the island. Genetic condition of the mineral inferred from its chemical composition may indicate submarine eruption of the volcano. 9) Three weak zones were recognized by the present investigations in addition to the two ones previously reported by Tsuya. Thus three are arranged radially through the center of the eastern main cone and the two are arranged concentrically around the foot of the same cone. From these weak zones phreatic explosions are expected in future, if they occur. 10) Nothing more than mere weak phreatic explosion was recorded through the historic activity of the volcano. Artificial filling up of the vent, such as the pavement of the surface often causes the small explosion at fumarole. 11) Submarine eruption recently found at the sea bottom, about 5.4 km NNE of the South Sulphur Island, about 50 km south of the island did not occur recently but must have repeated rather stationarily.According to the present investigations, no remarkable magmatic explosion could be expected except those small phreatic ones, same one of which has often occurred on the island. Chemical composition of the gases does not indicate any approach of hot magma to the surface.

著者

八木 勇治 菊地 正幸

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.112, no.6, pp.828-836, 2003-12-25 (Released:2009-11-12)

参考文献数

46

被引用文献数

1 5

---

Resent studies on relationship between sites for co-seismic slip and a-seismic slip are reviewed. Through analysis of seismic wave and Global Positioning System (GPS) data set, the sites for co-seismic slip and a-seismic slip have been obtained in Hyuga-nada and Sanriku region. Those studies show three important results : (1) the sites for co-seismic slip, episodic a-seismic slip, and continuous a-seismic slip do not overlap but complementarily share the plate boundary : (2) after-slip (post-seismic slip) may play an important role especially in the triggering large earthquakes : (3) the depth range of a-seismic slip may be controlled by not only a thermal effect but also some other factors such as lateral heterogeneity of fluidpressure and serpentinization.

著者

小原 一成

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.112, no.6, pp.837-849, 2003-12-25 (Released:2009-11-12)

参考文献数

20

被引用文献数

12 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

原 辰彦

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.114, no.3, pp.323-337, 2005-12-25 (Released:2009-11-12)

参考文献数

25

---

We review seismological studies on structure of the Earth's deep interior. First, we describe spherically symmetric Earth structure and discuss its geophysical implications. Second, we show three-dimensional mantle structure revealed by seismic tomography and discuss its geophysical implications. Then, we briefly review various anomalous and interesting features found in the lower mantle and the inner core.

著者

吉田 明夫 外谷 健 吉田 真希子

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.113, no.1, pp.107-124, 2004-02-25 (Released:2009-11-12)

参考文献数

39

被引用文献数

1 1

---

We investigated solar-cycle and semiannual variations of magnetic storms based on data observed at the Kakioka Magnetic Observatory since 1924. First, we show that magnetic storms with a peak value of ≥ 100 nT are considered to have been almost completely recorded for both types of storm, i.e., those with sudden commencement (Ssc) and those with gradual commencement (Sg). Using data for storms larger than 100 nT, we found that the variation of numbers of Ssc correlates well with that of the sunspot Wolf numbers, but that of Sg does not. The number of storms decreases linearly with the peak value in the semi-logarithmic plot. The inclination is steeper for Sg storms than for Ssc storms. The semiannual variation, that is, more storms are observed in spring and fall than in summer and winter, is clearly seen for storms with a peak value ≥ 100 nT for Sg, but it is recognized only for larger storms with a peak value ≥. 150 nT for Ssc. Concordant with the difference between Ssc and Sg in the semiannual variation, the decrease in the number of large storms in the semi-logarithmic plot is less in spring and fall than that in summer and winter for Ssc. Although such a difference is not apparently seen for Sg, the ratio of the number of storms with a peak value ≥ 150 nT to that of storms with a peak value between 100 nT and 150 nT is larger for spring and fall. We propose the hypothesis that the efficiency of magnetic reconnection depends on the three dimensional direction of the magnetic field in the solar wind relative to the geomagnetic field, and on the north-south symmetry of the geomagnetosphere when it is seen from the stream of the solar wind. We think these “equinoctial effects” are the main causes of the semiannual variation in the number of large magnetic storms. As for the Sudden Commencement (SC), the semiannual variation is not seen, but an annual variation with the number of SC being larger in summer is observed. The reason may be that the shock wave in the solar wind hits against the northern part of the geomagnetosphere in summer, and the southern part in winter.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.27, no.2, pp.184a-185, 1915

著者

駒澤 正夫 ホセ パンティーク エディー リスタンコ

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.123, no.1, pp.133-142, 2014

被引用文献数

3

---

イロシンカルデラの地下構造を把握するため1996年2月にBulusan火山およびその周辺で重力調査を実施した。測点は標高の低い山麓の道沿いに限られ,測定数は225点となった。火山の山体に近い密度である 2,300 kg/m³(2.3 g/cm³)の仮定密度のブーゲー異常図は,山体部に測点がなくても実際の重力異常を表すと考えられる。重力異常にはカルデラ壁に対応する急勾配がBulusan火山の東から南を経て西に存在することがわかった。しかし,カルデラの北縁については勾配構造が明瞭ではなかった。Irosin townは急勾配構造の内側にある低重力異常域にある。重力の3次元解析から得られた重力基盤にはカルデラ壁を含むカルデラ領域を示す直径 15 kmほどの円形構造があることがわかった。さらに,その円形構造の内側には直径 5 kmほどの急勾配の壁で仕切られた漏斗状(上下逆さまの円錐)の構造が存在し,深さは 1.5 kmに達することがわかった。つまり,イロシンカルデラは,陥没構造が一カ所だけ確認でき,大量の火山砕屑物の噴出を伴った大規模噴火(複数回の場合も含む)は,ごく狭い領域に限られることを示している。また,重力異常による質量欠損の計算から約 40 km³の領域から1.1 × 10¹⁰ トンの火山砕屑物を噴出したと推定され,既存のカルデラの直径と質量欠損の関係と整合的である。

著者

西川 治

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.112, no.3, pp.450-452, 2003-06-25 (Released:2009-11-12)