著者
小元 久仁夫
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.121, no.6, pp.1043-1051, 2012-12-25 (Released:2013-01-07)
参考文献数
36
被引用文献数
4

A large number of coral boulders are scattered on reef flats and along the shores of Sakishima Islands, SW of Japan. Many were considered to have been cast ashore by huge tsunamis. In this report the author analyzes the distribution and calibrates the 14C ages of coral boulders collected from Maibahbama, southeast of Miyako Island. The calibrated 14C ages indicate a random distribution; however, some coincided exactly with the 1771 Meiwa tsunami. The tsunami travelled from the epicenter northeast and struck the Higashihenna Promontory, then turned westward leaving a large numbers of coral boulders on Maibahbama. Judging from tsunami deposits overlaying the lowest marine terrace the wave height seems not to have exceeded 10m.
著者
若林 芳樹 伊藤 悟
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.103, no.3, pp.221-232, 1994-06-25 (Released:2009-11-12)
参考文献数
34
被引用文献数
2 6

Geographical approach to cognitive maps has mainly focused on measurement of their spatial patterns. Recently Lloyd (1989) devised a useful method for analyzing the components of distortions in cognitive maps by means of Euclidean regression. Until now, however, this method has not yet been validated. The purpose of this study was to reexamine his concepts about the distortions in cognitive maps and to test their validity.We pointed out several discrepancies between the concepts of distortions and their operational definitions given by Lloyd (1989). To overcome this problem, the absolute distortion that appears in the configuration before Euclidean regression ought to be distinguished from the systematic distortion that is measured by the parameters of Euclidean regression. While the systematic distortion that indicates a Euclidean property of the distortion can be explained by alignment and rotation heuristics (Tversky, 1981) and implicit scaling model (Holyoak and Mah, 1982), the relative distortion that remains after Euclidean regression cannot be explained by general theories. In addition, these geometrical components of distortion ought to be distinguished from statistical ones, namely, distortion (central tendency) and fuzziness (dispersion) defined by Gale (1982).On the basis of this conceptualization, we carried out an empirical analysis of the distortion in the cognitive map of Kanazawa City. The data used in this study were obtained by a conditional sketch mapping drawn from 113 students of Kanazawa University. Locations to be answered were 21 transportation nodes within the central part of the city known by more than 90 percent of the students. From these locations, two major landmarks of CBD were selected as reference points. Subjects were asked to indicate the remaining 19 locations on the legal-size sheet in which the two reference points were printed.We detected the absolute distortions, overlaying the cognitive maps for all samples on the actual map so as to fit the locations of two reference points into the actual ones. The patterns of the absolute distortion indicated that the amount of errors increased with distance from the reference points, and that the locations in cognitive maps commonly shifted outward from the actual ones. Specifically, these displaced locations in southern or eastern part of the city indicated a counterclockwise shift, which suggested a directional bias in cognitive maps.In order to separate the systematic distortion from the relative one, each of the cognitive configurations was fitted into the actual map by Euclidean regression. Parameter estimates of the scale change averaged 0.593, which suggested that cognitive maps were enlarged about twice the size of the actual map. Mean direction of the rotated angle amounted to-22.2 degrees, which implied that cognitive maps were rotated counterclockwise about 20 degrees from the actual map so as to coordinate the cardinal directions of the cognitive map with the actual one. This tendency can be due to the displacement of two river channels as major reference lines in Kanazawa from cardinal directions.After eliminating the systematic distortions by Euclidean regression, the actual map was overlaid with all the cognitive maps. The overlaid maps indicated that the local patterns of relative distortions reflected hierarchical structure of cognitive maps (Stevens and Coupe, 1978) although the amount of them was smaller than that of the systematic distortions.
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.95, no.4, pp.225-240, 1986-08-25 (Released:2009-11-12)
参考文献数
30
被引用文献数
1

IV. Research in geology of Manchuria i.e. Northeast China was commenced with RICHTHOFEN's trip in its southern part in 1869. In 1895 AHNERT's life work on the geology of Central and North Manchuria was started, and KOCHIBE carried out a preliminary survey in South Manchuria. Since 1923 geological papers of Manchuria were published by Y. C. SUN and others in Bull. Geol. Soc. China from 1923. Geological survey founded in South Manchurian Railway Company published Geological Map of South Manchuria, 1918 and Geology and Mineral Resources of the region, 1929. There are many papers in the regional geology written by Japanese geologists and palaeontologists.Besides late Permian naiads Silurian-Permian marine fossils were discovered in Central and North Manchuria and the Manmo group was proposed for the whole sequence of the Palaeozoic rocks accumulated in the Mongolian geosyncline. It was strongly disturbed by the Permo-Triassic orogeny accompanied by the Mongolian granite with the result that the area was consolidated and united with South Manchuria. Small basins were later brought about there and the large Liao-Sungari basin was produced in the late Mesozoic age. Recent studies by Chinese geologists reveal that the Manmo group comprises Cambrian and Ordovician fossils in its lower part and that it is rich in volcanic materials of different ages. Permian plants and lower and middle Triassic non-marine animals were discovered at some places. Further it is known that sea entered into the eastern part of Heilongjiang province temporarily in the late Triassic, middle-upper Jurassic and Cretaceous ages.V. PUMPELLY's geological reconnaissance in 1863-65 was the first in China, followed by RICHTHOFEN and others including Japanese geologists. The Tokyo Geographic Society published Geological Maps of South and North China and then of Eastern Asia all in 1 by 2 mills, scale in 1920, 1922 and 1929 respectively.According to E. T. CHANG (1922) mining was started in China already in prehistoric age. Chinese classics on stone medicine and related knowledge were imported to Korea and Japan. Among Chinese geologists CHANG was first to write geology of Chekiang, 1911. The Central Geological Survey at Nanking, Department of Geology in the National University of Peking and the Geological Society of China were successively founded in 1916, 1920 and 1922. Since then her geology advanced considerably except for some years from 1966. The research activity, however, became quite explosive from about 1973. The Geological Map of China in scale of 1/4 mills. was compiled in 1976 by the Chinese Academy of Geological ScienceAn outline of Tectonic characteristics of China and the Tectonic Map of China were published by T. K. HUANG and his cooperators in 1977 and 1979 respectively.Supplementary notes are given on the Pentsao and world map (1) and the growth of Asia documented in the expansion of the non-marine facies in the continent (2).

1 0 0 0 OA 丹後地震

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.39, no.4, pp.243-245, 1927-04-15 (Released:2010-12-22)

1 0 0 0 OA 捕鯨事業

著者
齋藤 半六
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.51, no.7, pp.300-312, 1939-07-15 (Released:2010-10-13)

1 0 0 0 OA 本朝地震考

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.10, no.9, pp.519-520, 1898-09-15 (Released:2010-12-22)
著者
手塚 章
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.121, no.4, pp.617-625, 2012

In the first half of the twentieth century, the French school of geography was very famous around the world, based on the reputations of its leading geographers (Vidal de la Blache, Martonne, Demangeon, etc.). French geography in the early twenty-first century, however, shows rather different perspectives from the Vidalien tradition of geography. In this paper, I attempt to describe some recent directions of this new French geography, mainly from the end of the 1970s. I pay special attention to eight French geographers to indicate the strong points of the present French geography, <i>i.e.</i> R. Brunet, Y. Lacoste, P. Claval, J.-R. Pitte, A. Berque, J. Lévy, R. Knafou, and C. Grataloup. These geographers have contributed to the recent renewal of French geography, especially in the areas of regional geography (la géographie chorématique), geopolitics, cultural geography, geography of tourism, and historical geography. I also mention new aspects of French geographical education.
著者
堤 浩之 Andrei I. KOZHURIN Mihail I. STREUTSOV 植木 岳雪 鈴木 康弘 渡辺 満久
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.109, no.2, pp.294-301, 2000-04-25 (Released:2010-11-18)
参考文献数
10
被引用文献数
3 6

We have mapped a series of north-trending faults along the northeastern coast of Sakhalin, Russia, based on aerial photograph interpretation and field observations. These faults include the Upper Pil'tun fault which ruptured during the 1995, Mw 7.0 Neftegorsk earthquake, and the Ekhabi-Pil'tun and Garomay faults east of the surface ruptures. The coseismic displacement associated with the 1995 earthquake shows that the Upper Pil'tun fault is a right-lateral strike-slip fault. Right-lateral stream offsets as much as 80m demonstrate that similar earthquakes have occurred repeatedly along the fault in the late Quaternary. The fault extends for 10 km further to the south beyond the southern termination of the 1995 surface breaks, which is consistent with the coseismic ground deformation detected by SAR interferometry. The Ekhabi-Pil'tun fault trends N10° W to N10°E with a series of fault scarps down-to-the-west across low-relief hilly terrain eroded byperiglacial processes. Right-laterally offset streams and lake shores suggest thatthe Ekhabi-Pil'tun fault is also a right-lateral strike-slip fault. A 3-m-deep trench across the fault north of the Sabo River contains geologic evidence of two episodes of pre -historic surface faulting. The most recent event occurred after 4000 yr B.P. and the penultimate earthquake occurred at about 6200 yr B.P. The interval between the events is greater than 2000 years, which is significantly longer than that obtained for the Upper Pil'tunfault by previous trench excavations.
著者
亀田 純 木村 学 O. A. MELINIKOV 早坂 康隆 橋本 善孝 坂島 隆彦 新井 孝志 芳野 極 鈴木 紀毅
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.109, no.2, pp.235-248, 2000-04-25 (Released:2010-11-18)
参考文献数
21
被引用文献数
4 7

The region from Sakhalin in Russia to the eastern margin of the Japan Sea has been regarded as a convergent plate boundary zone between the Eurasia and the North America Plates because large earthquakes and active crustal movements are prominent in this zone. These activities along the eastern margin of the Japan Sea to southern Sakhalin are almost consistent with the expected relative plate motion deduced from the Euler pole which is estimated from the magnetic anomaly lineations in the Atlantic Ocean, but the modern tectonic aspect in northern Sakhalin is inconsistent; e.g., 1995 Neftegorsk Earthquake is one of the typical events.As a result of a structural and tectonic study in northern Sakhalin, the NE-SW compressive tectonic feature since the Late Miocene was clarified. In the northernmost area of the Schmidt Peninsula, the early Cretaceous ophiolite thrusts upon the Late Cretaceous sedimentary rocks. The ophiolite has an overturned sequence: serpentinites, gabbros, basaltic rocks, and hemipelagic sediments in descending order. The Cretaceous sediments form a map-scale and NW vergent synclinorium. All the deformation structures in outcrop scale, such as micro-folds, minor reverse and normal faults, axial plane cleavages and bedding slips, are consistent with a large scale folding. These structural relationships suggest only one event of deformation, which appears to be linked to overthrusting of the ophiolitic rocks.A structural investigation of the southeastern part of the Schmidt Peninsula revealed that the Middle Miocene sediments composed of siltstone and sandstone are folded with wavelength of several tens to several hundred meters. Their fold axes trend in the NW direction, which indicates that deformation under the NE compression is the same as the deformation in the northernmost area. The thickness of sedimentary layers are constant everywhere in folding. This fact indicates that the timing of the deformation is after sedimentation, that is, after the Middle Miocene. This deformation event is consistent with modern activity in northern Sakhalin. Therefore, the modern tectonic framework might have started in the Late Miocene time.A plate tectonic model indicates that the modern relative motion between the Eurasia and the North America Plate started at about 11 m. y. ago. The Late Miocene onset of the modern tectonic framework in northern Sakhalin occurred at almost the same time. The most reliable model to explain the discrepancy of sense of movement from the Eurasia-North America retative motion, may be the “extrusion” of the Okhotsk Block toward the Pacific Ocean. The dextral extrusion boundary in northern Sakhalin may be traced along theeastern coast of Sakhalin to the northern edge of the Kuril Basin, where active seismicityhas been observed although a detailed study of focal mechanisms and other tectonic aspects is needed in the future.
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.122, no.2, pp.Cover01_1-Cover01_2, 2013

1990~1995年に噴火した雲仙普賢岳で,その噴火のメカニズムを解明するための火道掘削を2002~2004年に実施した.この掘削は国際陸上科学掘削計画(ICDP)からの資金援助を得て行われた.(左上)雲仙普賢岳の平成噴火(1990~1995年噴火)火道を掘削した,雲仙科学掘削プロジェクト(USDP)リグサイト(USDP-4)での作業風景.背景の裸岩部分は平成噴火で形成された溶岩ドーム(標高約1400m).普賢岳山頂の北約1km,標高840mにあるこのサイトから山頂直下に向かって斜めに掘り進んだ.2004年6月撮影.(左下)普賢岳の北斜面につくられたUSDP-4リグサイト.櫓の高さは約55m.山頂の溶岩ドームから2003年11月撮影.(右上)複合岩脈である火道域において採取されたコア試料.マグマ上昇中にできた火山角礫岩中の火砕岩脈(タフサイト).掘削深度1748m(標高約-100m).横幅約13cm.(右中)掘り当てた平成噴火の火道溶岩(デイサイト).掘削深度1977m(標高約-150m).すでに熱水変質が進んでいる.横幅約4cm.(右下)火道溶岩の顕微鏡写真.融食構造をもつ石英斑晶.横幅約2.5mm.(写真・解説 中田節也)
著者
吉田 明夫 伊藤 秀美 細野 耕司
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.105, no.1, pp.77-87, 1996-02-25 (Released:2009-11-12)
参考文献数
22
被引用文献数
2 2

Several examples are presented which seismic quiescence appeared in a wide area around the foci of intraplate earthquakes before their occurrence. A noteworthy feature is that the quiescence area extends along tectonic zones over more than several times of the focal region of the main shock. This phenomenon suggests that stress in a wide area along tectonic zones changes before the occurrence of major intraplate earthquake. We consider that the stress change is a manifestation of a significant physical process leading to earthquake occurrence. An apparently puzzling fact which earthquake precursors are sometimes observed at distant places from the focal region in the specific direction may be explained by such stress change. Further, it is expected that the precursory seismic quiescence provides us with a promising clue to the short-term prediction of intraplate earthquake.
著者
相馬 清二
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.84, no.4, pp.204-217, 1975
被引用文献数
3 3

A violent fire-tornado has broken out at the former site of the Army Clothing Depot in combustion caused by the destructions of the Great Kanto Earthquake at 3.30 p.m. September 1, 1923. By this fire-tornado, about 40 thousand people have been burned to death in a moment. An interpretation that the fire-tornado has been caused by passage of a cold front has generally dominated academic circles in this field up to date. According to the detailed reexaminations, this interpretation included many inconsistencies. We could obtain recently the various data with respect to the fire-tornado which occurred in the last several years. From these data, it became clear that the fire-tornadoes often have occurred near a combustion area.<BR>An example which was the most similar with the fire-tornado at the former site of the Army Clothing Depot was found out in the combustion of Wakayama City by an air raid on July 9, 1945. 748 persons have been burned to death by the fire-tornado in this city.<BR>Finally, our study leads to the conclusion that the fire-tornado at the former site of the Army Clothing Depot was caused by the widespread great fire following the Great Kanto Earthquake. There was a cold front in northwestern direction of Tokyo, but it did not play the leading role for formation of the fire-tornado.
著者
森 慎一 藤岡 換太郎 有馬 眞
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.119, no.4, pp.585-614, 2010-08-25 (Released:2010-11-08)
参考文献数
89
被引用文献数
2 6

This paper describes topographic and geologic features of the northern part of the Sagami Trough and surrounding areas, off central Japan, and discusses the role of the Philippine Sea plate in the development of the trough's topography and fault systems. In the study area, the Okinoyama Bank Chain, Miura Basin Chain, and several spurs are aligned NW-SE parallel to the axis of the Sagami Trough. We examine the lithological compositions of rock and piston-core samples collected from the R/V Hyper Dolphin during Japan Agency for Marine-Earth Science and Technology dives 906 and 907, and rock samples dredged during Ocean Research Institute of the University of Tokyo cruise KT88. These samples represent mainly volcaniclastic rocks derived from the volcanoes of the Izu arc and subordinate amounts of terrigenous sediment interpreted as derived from the Sagami and Sakawa Rivers. The topographic and geologic data define five fault systems in the eastern part of the northern Sagami Trough. We interpret the Okinoyama Bank Chain as an elevated outer-ridge belt developed at the landward slope of the plate boundary, which is represented by NW-SE trending right-lateral reverse faults (F1). At the northeast side of the Okinoyama Bank Chain, NW-SE trending normal faults (F2) formed and the Miura Basin Chain developed. The cutting relationship between these fault sets suggests that the collision of the Izu arc with the Honshu arc imposed a right-lateral shear stress field on the Okinoyama Bank and Miura Basin Chains. This shear stress may have led to clockwise rotation of these tectonic blocks formation of a set of NE-SW trending left-lateral reverse faults (F3). The initiation of the Izu block collision is interpreted as a turning point after which the northward motion of the Philippine Sea plate abruptly changed to NW and the Sagami Bay area came under a NW-SE compressional stress field, which resulted in the development of E-W trending right-lateral faults (F4) in the narrow shelf off the Miura Peninsula. A number of spurs subsequently developed along these faults. Finally, NNE-SSW trending right-lateral normal faults (F5) developed under an E-W extensional stress field, which caused the formation of N-S trending topographic depressions such as Tokyo Canyon and submarine highs such as Okinoyama and Oiso Spur.
著者
本郷 宙軌
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.119, no.5, pp.860-871, 2010-10-25 (Released:2011-01-21)
参考文献数
23
被引用文献数
1 2

Coral reef terraces are one of the best recorders of biological response to environmental change events (e.g., sea-level changes). Kikai Island provides a rare opportunity to show biological and ecological frameworks (e.g., competition, coexistence, and succession) during a recent geological period. The island is fringed by raised Holocene raised reef terraces, which formed as a result of periodic tectonic uplifts. This study aims to characterize the spatial and temporal changes of corals at this island during the Holocene. The analysis is based on topographical and biological data obtained for the three sites (Shidooke, Kadon, and Nakugama reefs). Three raised reef terraces (Terrace II, III, and IV) grew from 7300 to 4500 years ago (during 2800 years), from 4500 to 2900 years ago (during 1600 years), and from 2900 to 1800 years ago (during 1100 years), respectively. Terrace II and III were uplifted 1-2 m around 4500 years ago and around 2900 years ago. Terrace IV was uplifted 1-2 m around 1800 years ago. The modern reef has been composed of corals for 1800 years. Sixteen coral genera and 53 species were recorded from the reef terraces. Terrace III and IV were dominated by four coral species (A. digitifera, A. robusta, G. retiformis, and F. stelligera), but Terrace II was predominantly composed of A. digitifera and A. robusta. These biological and ecological variations between the terraces represent a growth strategy responding to differences of reef growth time and/or insolation.
著者
竹内 常行
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.84, no.1, pp.1-19, 1975-02-28 (Released:2009-11-12)
被引用文献数
8 7

When making paddy fields on a slope, the paddies, each with a level surface, must be made one by one in the form of a series of shelves or terraces. Paddy fields made in this manner are called “terraced paddy fields” or “shelf paddies” “tanada” in Japanese. Such paddy fields are found in various parts of the mountainous regions of Japan, and may roughly be divided into two categories, depending on the nature of the place where they are found. The first category includes terraced paddy fields that stretch in long, narrow lines along the bottom of small valley among the mountains. To the second category belong those that are found stretching on wide slopes. Terraced paddy fields belonging to the first category are found everywhere in mountainous regions. They are easy to make and their irrigation presents no problems. In the case of terraced paddy fields of the second category, however, because of the general complexity of the relief of the slopes where they are found, their making in such places requires great labor, and their irrigation is a difficult matter.The present writer conducted a study of 26 of the main terraced paddy fields belonging to the second category, and in each case, was convinced of the great pains and resourcefulness required to ensure the supply of irrigation water.In Japan, rice has been the main food crop since ancient times ; and until the Meiji period, it was the practice among farmers to pay their taxes in rice. Rice was the all-important element of economy, both for the central and local feudal lords until the Meiji period. This was the reason that, throughout the nation, the development and expansion of paddy fields were the two main concerns of the rulers as well as the farmers. This state of affairs continued until recent times. The present writer believes that it is possible to consider the existence of terraced paddy fields as one of the manifestations of the history of this type of rice-centered policy in the form of cultural landscapes seen in the land.In the present paper, the writer has chosen three typical regions, and he purposes to describe the development of the irrigation of the terraced paddy fields found in each of these regions.(1) The Wajima Region in the northern part of the Noto Peninsula.This region is the location of “Shirayone no Senmaida” (or “Numerous Small Terraced Paddy Fields of Shirayone”), which in recent years have come to attract the attention of tourists. There are monographs and books which state that the terraced paddy fields in this region are supplied with irrigation water by springs and rain water. The writer, however, has made clear in the present paper the fallacy of these claims. In the Edo period, in order to irrigate the terraced paddy fields in this region, long irrigation canals were dug to draw irrigation water from the upper reaches of rivers among the mountains, while irrigation reservoirs were made among the mountains to provide irrigation water. Examples of these irrigation systems are shown in Figures 1 and 2. The terraced paddy fields in this region are developed on slopes formed as a result of landslides.(2) The Obasute Region in Nagano Prefecture.This region is the location of terraced paddy fields widely reputed as “Tagoto no Tsuki” (or “The Moon Reflected in Each of Many Paddy Fields”). In this region, too, are found terraced paddy fields on slopes formed as a result of landslides. Concerning the terraced paddy fields in this region, there are books which state that they were supplied with irrigation water by springs and rain water, but the irrigation system in this region is not such a simple matter.
著者
衣笠 善博
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.1, pp.13-17, 1990-02-25 (Released:2010-11-18)
参考文献数
16
被引用文献数
1 1 3

The hypothesis proposed by Nakamura (1983) that the North-Eastern Japan is a part of the North-American Plate has been re-examined from geological and geomorphological veiw points. One of the difficulties is that active faults are not found along the entire length of the Itoigawa-Shizuoka Tectonic Line which is considered as the boundary between rigid plates. The beginning of the convergence at the Itoigawa-Shizuoka Tectonic Line is much older than the age speculated by SENO (1987). An alternative hypothesis that the Itoigawa-Shizuoka Tectonic Line is a moribund plate boundary is proposed.