著者

増田 富士雄

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.419-433, 2005-12-25 (Released:2009-11-12)

参考文献数

67

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A new research field is introduced for strata science in geology. The new stratigraphy is that a layer, a bed and/or a band of “a year, a month, a day, and several hours” we actually experience everyday, are defined from strata. In this paper we introduce the following four case studies of high-resolution determination for 1) annual beds, 2) historical river-flooding beds, 3) tidal bands, and 4) cross-beds. We also describe new information obtained from the results of these high-resolution stratigraphic studies, which include : discovery of millennial oscillations of solar cycle from the 500 Ka lake varves (annual beds) date determination of every fluvial-flooding beds from the intercalated human wastes and, 600-million-year history of Earth's rotation detected from an annual band in fossils and tidal beds in strata.

著者

町田 尚久

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.123, no.3, pp.363-377, 2014-06-25 (Released:2014-07-03)

参考文献数

31

被引用文献数

1

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To clarify the cause of heavy rains and weather related to a famous disaster that occurred in 1742, the weather sequence and its spatial distribution were investigated on the basis of local historical documents obtained from various areas of central Japan. As a result, the eastward movement of a typhoon was reconstructed in the sea off the south coast of central Japan. It was accompanied by an inflow of moist air around the eastern fringe of the typhoon, which brought about a rain zone extending from Kinki to Kanto from 27th Jul. to 1st Aug., according to the lunar calendar used at that time. The typhoon abruptly turned north when it reached southern Kanto and proceeded north across Honshu. It was accompanied by heavy rains and strong winds on 1st and 2nd Aug., which were recorded in central and western Kanto and areas further north. The abrupt change of direction seems to have been caused by a strong anticyclone that is thought to have extended to the east coast of Kanto. Although this situation around an anticyclone occurs frequently in late Summer, not enough evidence has been obtained yet on the situation at that time. The heavy rains and induced landslides caused floods particularly in the Ara, Tone, and Chikuma river basins. This is a matter of concern from the viewpoint of a fluvial geomorphic system analysis.

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.104, no.1, pp.45-68, 1995-02-25 (Released:2010-11-18)

参考文献数

84

被引用文献数

3 5

---

A multi-disciplinary synthesis was made on the tectonics and seismotectonics in the northwestern Sagami Bay and adjacent areas, where the plate boundary between the Izu-Bonin and Northeast Japan arcs passes and historical M7-8 inter-and intraplate earthquakes frequentlyhave occurred.In a convergent boundary between plates, a displacement between plates is usually accommodatedalong a broad belt of active imbricated thrusts and folds, which develop in a wedge ofan overriding plate. In such a situation, we can easily identify two kinds of plate boundaries: a deformation front and a subduction entrance. The deformation front is a line connecting thethrusts or folds nearest to a trench/trough axis. The subduction entrance is a line connecting theedges of trench/trough filling coarse deposits, which cover a surface of a subducting plate. In Sagami Bay, the deformation front in the overriding Northeast Japan arc is estimated to belocated along the northern and eastern edges of the Sagami Basin, while the subductionentrance of the subducting Izu-Bonin arc is estimated to be located along the southern edge of the Basin.Many geomorphological, geological, geophysical observations need and support the existenceof the West Sagami Bay Fracture (WSBF), an intraplate propagating fracture between the Izu-Bonin outer and inner arcs, proposed by Ishibashi (1988), whereas these observations require slightmodification of the estimated geometry around the WSBF. Frequent dike intrusions in theHigashi Izu monogenetic volcano field cause spreading of the upper crust and probably move the Manazuru “microplate”(MNZ) to the NNE direction against the Izu block. The Tanna-Hirayama tectonic line is proposed as a transform fault, which accomodates the relativemovement between the MNZ and the Izu block. In the MNZ hypothesis, the Kozu-Matsuda fault, located to the northeast of the Izu Peninsula, is interpreted as a deformation front between theoverriding Northeast Japan arc and the MNZ, which is buoyantly subducting beneath the Oiso Hilland Tanzawa Mountains. The proposed new geometry around the WSBF and the hypothesis of the MNZ can explain (1) the crustal structure and tectonic features around the Kozu-Matsudafault, (2) tectonic implication of the “Oiso-type” earthquakes, which are expected to displacethe Kozu-Matsuda fault periodically, and (3) the rapid upheaval of the Tanzawa Mountains since 1Ma.

著者

山崎 直方

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.17, no.1, pp.5-20_2, 1905-01-15 (Released:2010-10-13)

著者

佐藤 昌人 八反地 剛 松岡 憲知

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.1, pp.133-153, 2016-02-25 (Released:2016-03-22)

参考文献数

168

被引用文献数

4 3

---

Weathering processes on Martian surface are among the essential issues for both understanding landform evolution and exploring water availability on Martian surface. Studies are reviewed on various weathering processes on Martian surface based on images, data collected by rovers, and laboratory approaches. Recent explorations by the Mars Exploration Rovers reveal that chemical weathering occurs on the surface of basaltic regolith. Dissolution of olivine and oxidation of Fe produces weathering rinds on basaltic surface regolith. Rock interiors also show vugs and veins filled with light-toned efflorescence indicative of chemical weathering. In particular, in high-latitude areas the two Viking landers and the Mars Pathfinder observed honeycomb weathering, angular rock fragments, and polygonal cracks in bedrock. Most of these features are also observed in the Antarctica and other cold deserts on Earth, and are generally attributed to physical weathering such as salt crystallization, thermal weathering, and/or frost weathering. Some studies successfully estimate periods and rates of weathering on the Martian surface, which promote a further understanding of environmental changes and landform evolution.

著者

矢島 道子

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.114, no.4, pp.609-613, 2005-12-25 (Released:2009-11-12)

参考文献数

6

著者

金田 楢太郎

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.4, no.2, pp.78-81, 1892-02-25 (Released:2010-10-13)

著者

田林 雄 山室 真澄

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.121, no.3, pp.411-420, 2012-06-25 (Released:2012-07-09)

参考文献数

40

被引用文献数

4

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Nitrogen compound deposition as a result of human activities on the terrestrial surface has increased sharply during the last one hundred years, causing ecological problems. One problem is nitrogen saturation in forest ecosystems, which results in the forest ecosystem receiving more nitrogen than required. In recent years, nitrogen oxide emissions have been decreasing in Japan; however, the total deposition of nitrogen is not decreasing because of cross-boundary emissions from other countries. As depositions in forest ecosystems increase, the likelihood of nitrogen saturation increases. At the same time, certain species of trees, geological conditions, and climate will affect nitrogen saturation. In Japan, there is heavy precipitation in summer; therefore, decreases in nitrate concentrations of stream water cannot be observed. Stable isotope analysis is the key to elucidating nitrogen dynamics between the atmosphere and rivers. From the atmosphere to stream water, nitrogen compounds have many chemical and biological reactions. Because a stable isotope is an indicator of the progress of these reactions, frequent analyses of stable isotope compositions reveals how nitrogen moves from the atmosphere to stream water.

著者

鈴木 富之

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.3, pp.466-485, 2011-06-25 (Released:2011-09-06)

参考文献数

42

被引用文献数

2 5

---

Many business travelers often stay in large cities because of the concentration of various urban functions. The number of foreign tourists visiting Japan has increased in recent years. The main destinations are metropolitan areas such as Tokyo and Osaka. Given this situation, it is necessary to develop cheaper accommodations for foreign and business travellers who want to stay in those areas for long periods. The purpose of this study is to examine the characteristics and factors behind the evolution of accommodations in the Sanya district, which is located in an “inner-city” in Tokyo. Cheap lodging houses in Sanya have been in decline since the collapse of Japan's asset inflation-led economic bubble in the early 1990s. Managers of accommodations started to accept foreign and business guests. These accommodations have attempted to differentiate themselves from hotels located in central Tokyo in terms of service and lower tariffs. The following three reasons, which this study clarifies, help explain why accommodations in the Sanya district have evolved. First, Sanya was traditionally developed as a “Yoseba”, a place in which day laborers lived. In addition, Sanya is located close to central Tokyo. Secondly, due to a decreasing number of day laborers, cheap lodging houses had empty rooms. Therefore, their managers started to accept foreign tourists and business travellers. In addition, various mass media started to report favorably on Sanya during the World Cup Football games in 2002, although the Sanya district previously had a negative image. Lastly, many foreign tourists began to stay in the area after the World Cup.

著者

楮原 京子 田代 佑徳 小坂 英輝 阿部 恒平 中山 英二 三輪 敦志 今泉 俊文

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.221-241, 2016-04-25 (Released:2016-05-12)

参考文献数

47

---

We should understand the earthquake potential in and around Quaternary fault zones, in view of recent destructive inland earthquakes at previously unknown active fault zones in Japan. The Senpoku Plain and its surrounding areas are characterized by high seismic activity in northeast Japan, highlighted by four destructive earthquakes, M 6.8 in 2008, M 6.4 in 2003, M 6.5 in 1962, and M 7.0 in 1900, which occurred during the past 100 years, although few geomorphic features indicate active faulting. A comprehensive survey was conducted on the tectonic geomorphology in the area to understand the structural and geomorphic expression of the Ichinoseki–Ishikoshi Flexure Line (IIFL), which suggests Quaternary activity. Geological and geomorphical mapping shows that the IIFL is located between the Kitakami Lowland Fault Zone and the Senpoku Plain. The IIFL extends about 30 km from Isawa to Ishikoshi with a slightly sinuous trace. A high-resolution seismic reflection profile and a gravity profile define the subsurface geometry of the IIFL. The IIFL is interpreted to be a steeply west-dipping reverse fault. The Pliocene Kazawa and Yushima Formations typically dip 40° to 20°E along the IIFL, and are overlain by the Pleistocene Mataki Formation, which becomes thinner toward the fold axis of the IIFL, and their dips decrease progressively upward. This suggests that the Mataki Formation was deposited concurrently with fault activity of the IIFL. Fission-track dating of a tuff layer within the uppermost section of the Kazawa Formation indicates that active reverse faulting of the IIFL began at about 2 Ma. At least 280 m of the tectonic uplift is consumed by active faulting and the average uplift rates are estimated to be 0.14–0.08 mm/yr. Vertical separations of Hh surface are about 15 to 40 m. Heights of fold scarps on L1 surface are about 2 m. Their ages are determined to be 0.4–0.5 Ma for Hh and 24–12 ka for L1, respectively. Therefore, the Quaternary average uplift rates of the IIFL are estimated to be 0.03–0.17 mm/yr. Quaternary activity of the IIFL is weak, but there are differences in the magnitude of dissection in the Iwai Hills between the hanging-wall and the footwall of the IIFL.

著者

花輪 公雄

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.485-495, 2005-12-25 (Released:2009-11-12)

参考文献数

12

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The oceans play important roles in the formation of the earth's climate, and in climatic variations and change. One of these important roles is meridional heat transport due to oceanic general circulation, especially three-dimensional thermohaline circulation through the entire water column. The oceans transport a huge amount of heat-as much as that of the atmosphere. Accordingly, the north-south gradient of surface air temperature is greatly mitigated. Corresponding to global warming due to increases of greenhouse gasses, the oceanic heat content hasincreased sharply. Global warming might cause a weakening of the strength of thermohaline circulation.

著者

亀倉 正博

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.112, no.2, pp.262-276, 2003-04-25 (Released:2009-11-12)

参考文献数

82

被引用文献数

1 1

---

Extreme halophiles (halobacteria) are microorganisms that require a high concentration of NaCl for their optimal growth. They belong to the domain Archaea, together with methanogens and some thermophiles. It has been shown that halobacterial cells are entrapped within the fluid inclusions when NaCl crystallizes, and viable cells could be recovered after many months. Many halobacteria have been isolated from Permian halite, however, few studies are generally accepted due to questions about sample quality and contamination.A recent report that a halophilic bacterium was isolated from a fluid inclusion within a primary salt crystal of the Permian (250 Ma) suggested again that previously reported isolations of halobacteria from Permian halite might be true. The requirement for elevated salt concentration, the probable ability to survive within low water activity environments for long period, and the presence of concentrated KCl in the cells, which is shown to protect DNA and proteins from harmful irradiation, makes halobacteria likely candidates for life on early Mars.

著者

坪井 九馬三 神保 小虎 箕作 元八 野口 保興 磯田 良 山崎 直方

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.14, no.12, pp.a1-a46, 1902-12-15 (Released:2010-10-13)

著者

後閑 文之助

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.88, no.2, pp.63-87, 1979-04-25 (Released:2009-11-12)

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Japanese historical and geographical literatures, the Kojiki, the Nihongi, the Fudoki etc., were edited in the 8th century. Studies of minerals, rocks and fossils at that time were done on the basis of the Honzo (Pen-Tsao), Chinese ancient pharmacy. Since the 17th century studies of the Honzo were settled in Japan and progressed independently. With the development of the Japanese industry in the end of the 18th century, the Meibutsu-gaku, or the Bussan-gaku, learning on natural material or product, originated from the Honzo. On the other hand, since the end of the 17th century, Western natural sciences were transmitted to Japan through Dutch Commercial Office in Nagasaki. The eastern sciences such as the Honzo and the Bussan-gaku resulted in the establishment of the modern geology in Japan together with the western sciences.

著者

岩森 光 行竹 洋平 飯尾 能久 中村 仁美

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.128, no.5, pp.761-783, 2019-10-25 (Released:2019-11-15)

参考文献数

116

被引用文献数

2 3

---

A total of one to ten ocean masses of water (including H2O, OH, H in gas, liquid, and solid phases) is probably stored in the Earth's crust-mantle system as a variety of forms and components. Of these, the liquid phase involves aqueous solution, hydrous melt, and supercritical fluid, which may change composition continuously from a diluted aqueous fluid to a silicate melt above the second critical endpoint. These fluids are termed “geofluids” in this review paper, which describes physicochemical conditions required for the presence of geofluids, their compositions, and related tectonic setting and geodynamic phenomena. On the basis of the maximum water content that can be stored in crust-mantle rocks, subduction zone processes are discussed in which slab-derived fluids that are enriched in solid components play important roles: viscosity-flow-thermal field and melting in the mantle wedge, and origin of deep-seated fluid such as Arima-type brine. The fluid flux in the arc crust may be captured by geophysical and geochemical observations, such as seismicity, seismic velocity, electrical conductivity, and helium isotopic ratios. Several specific phenomena such as migrating seismic events and localized crustal deformation may be attributed to such fluid fluxes from the depths, which have been induced by an elevated fluid pressure and a reduction of rock strength and viscosity.

著者

立平 良三

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.111, no.5, pp.780-782, 2002-10-25 (Released:2009-11-12)

参考文献数

4

著者

田口 洋美

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.113, no.2, pp.191-202, 2004

被引用文献数

2 1

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It is generally assumed that the Japanese society and culture have been developed on the basis of the agriculture, especially on the rice field cultivation. Hunting, therefore, has been considered a sub-culture insignificant in the socio-cultural context as a whole. The author, however, is of the opinion that the two activities, agriculture and hunting, which are seemingly unrelated in outlook, have been strongly linked and have played complementary roles to each other.<BR>Japanese traditional hunters, Matagi, played an important role here as semi-professional hunters, and their hunting has increasingly become market-oriented.<BR>Agricultural activities inevitably destroy the natural habitat of wildlife by reclaiming or clearing forests to make the land suitable for cultivation, thus eliminating wild animals. Ironically, however, crops grown on cultivated land, which are rich in nutrition, attract wild animals. If the farmers intend to keep high productivity, those animals must be efficiently expelled from the man-controlled area. Agriculture is simply incompatible with wild animals.<BR>Hunting for a living, on the other hand, in essentially to capture wild animals, they are either consumed as various resources by the hunter himself or sold or exchanged for the necessities of life. To ensure sustainable hunting, the number of wild animals must also be sustained, which means the number of captures and the reproduction of animals must be well balanced. Hunting activities thus inevitably require coexistence with wildlife.<BR>Hunting and the agriculture, contradiction in principle, however, could and actually have cooperated to form a complementary relationship, which could be called a system : the hunters eliminated wild animals from cultivated land, and the crops attracted game animals for hunting. Around the peripheries of cultivated areas such complementary relationships have been and still are sustained.<BR>Historically, such relationships were gradually established from 17<SUP>th</SUP> to 18<SUP>th</SUP> centuries, when the Edo Shogunate encouraged as its policy to expand agricultural lands. With the technological advances of irrigation systems, marshlands and shoals were turned into rice fields in the plains, and hills and valleys were cultivated in the mountain regions. Hunting then gradually became involved in the agricultural activities to protect farmland from wild animals.<BR>In the later period of the Edo Shogunate, the farmers themselves began to capture or chase wild animals out of farmland. At the same time, some hunters with highly professional hunting techniques began further chasing and hunting game animals beyond the cultivated lands. Villages experiencing greater damage from wild animals often hired such hunters. The resources obtained from the captured animals and birds, such as furs, hides, feathers, tendons, meat, and internal organs and bones for medical use, were supplied to the local markets. Hunting thus found its niche at the peripheries of agriculture and the market that demanded animal resources, though limited in quantities and in the number of consumers the market might have been.<BR>The flow of animal resources, from agricultural land, to the hunters, then to the market, seems to have been established as a system around 18<SUP>th</SUP> to 19<SUP>th</SUP> centuries, as the monetary system began to prevail and currency was widely used.<BR>As Japan turned into the Modern Ages, hunting became more market-oriented and also strictly controlled : hunting was encouraged to supply furs for export to Europe and the US, and for the military use under the Imperial militaristic government at the time.<BR>A historical review of hunting in Japan suggests that, as for the conservation of wildlife, a historical and socio-cultural viewpoint is essential along with ecological and ethological research.

著者

生駒 大洋 玄田 英典

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.116, no.1, pp.196-210, 2007-02-25 (Released:2009-11-12)

参考文献数

47

被引用文献数

1

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Although the mass of oceans on the Earth is a tiny fraction (0.023 wt%) of the bulk Earth mass, the existence of oceans is sufficient to distinguish the Earth from the other planets in the solar system. Water is essential for the origin and evolution of life, the stability of the surface environment, and the evolution of the planetary interior. At present, we have no definite answers to fundamental questions about the origins of water on the Earth. The process by which water was supplied to the Earth is thought to be closely related to the dynamics of the solar system. Because of several uncertainties about the planet formation process (the position of the snow line in the solar nebula, the lifetime of the nebula gas, the timing of the formation of Jupiter, etc.), the origins of the Earth's oceans are still much in question. In this paper, we describe several possible sources of the Earth's water in the solar system and possible processes by which water was supplied to the Earth. Within the context of the modern theory of planetary formation, we discuss several scenarios for the origins of the Earth's oceans.

著者

澤田 可洋

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.111, no.3, pp.374-394, 2002-06-25 (Released:2009-11-12)

参考文献数

44

被引用文献数

8 7

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The detection rate of eruption cloud with Geostationary Meteorological Satellite (GMS ; HIMAWARI in Japanese) is 12.1%, but GMS can detect and track, at a high rate of 81.5%, eruption cloud from a large explosive eruption higher than 10 km which may threaten aviation safety.Estimates of the top altitude of eruption clouds within the tropopause based on cloud-top temperature show fairly high values compared to those obtained by ground observations. Growth of vapor clouds over eruption clouds induced by strong ascending currents with eruption-onset may be the reason.Apparent dislocation of eruption clouds on GMS images due to the parallax of GMS is clarified for the case of the 1986 Izu-Oshima Eruption, Japan, and the underestimation of cloud-top is possibly due to warming of the cloud-surface by radiation from internal hot material.From inspections of the pattern of cloud-extent, type, strength, decay, and duration of eruption activity can be evaluated.Differential Thermal Infrared Imagery of GMS-5 is very effective for discriminating ashbearing cloud from ambient atmospheric cloud, but cannot clearly separate an eruption cloud with an extremely high content of water-vapor with phreatic/phreatomagmatic eruption.

著者

浜野 一彦

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.91, no.2, pp.69-87, 1982-04-25 (Released:2010-10-13)

参考文献数

9

被引用文献数

1

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The geological formations of Mt. Fuji are composed of Pre-Miocene, Miocene, Pliocene and Komitake, Fuji volcanic ejecta.The following table shows the geological formations of this region.Pre-Miocene, Miocene and Komitake volcanic ejecta lie beneath Mt. Fuji. These rocks are the foundation of Fuji volcano.The first building of Fuji volcano started by Kofuji volcanic mudflow which covered the Komitake volcano and older rocks. The second eruption is made up of a sequence of Younger volcanic ejecta, which cover on alluvium sequence.The sequence of ejecta is L1-T1-L2-T2-L3-L4-T3 layers, except for L4 and T3 layers they all erupted from summit fire crater. L-layer is composed of the lava and tephra alternation and T-layer, which has the most of tephra. These limits make up the stratified volcano.The flanks of mountain are sculptured by a number of radial valleys but they not have surface streams. The largest valley is “Osawa” and the second is “Yosidaosawa”, both integrated these valleys are now growing. These valley are eroded by streams of the heavy rainfall, flow of underground water and by snowslides. Osawa is a V-type erosion valley and Yoshidaosawa is a U-type wallerosion valley.On the flank of the mountain, rainwater sinks into the ground and is stored on the surface of the unpermeable layers (Kofuji volcanic mudflow) as the underground water. It runs downward and flows out at the mountain foot. From the cliff, which outcrips at the top of Yoshidaosawa, large rock fragments fall and roll on the valleyfloor. Summer in 1980, twelve persons were killed by such rockfall. This rockfall happened by the increase of the undergroundwater pressure which made the rock fragments on the near cliff unstable and caused the disasterous rockslides.