著者
鹿園 直建
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.360-373, 2002-06-25 (Released:2009-11-12)
参考文献数
31
被引用文献数
1

Previous studies such as that of Meybeck (1987) estimated the CO2 flux from atmosphere to riverwater due to chemical weathering by assuming that the rate of weathering of silicate rocks and carbonate rocks is proportional to the surface areas of rocks (silicate rocks : carbonate rocks = 7 : 3). However, the dissolution rate of carbonates (calcite and dolomite) is in two to four orders of magnitude higher than silicate (feldspar). This may imply that Meybeck's and other previous approaches lead to a large uncertainty in the estimate of CO2 flux. However, their estimates are nearly similar to that of Gaillardet et al. (1999), who estimated the contribution of the weathering of silicates and carbonates to riverwater chemistry based on a large volume of analytical and runoff data of the world's 60 major rivers.The thermochemical calculation in the present study indicates that the chemistry of riverwater having a small runoff is controlled by the solubilities of calcite and Na ·Ca-feldspar (Na : Ca = 1 : 1) at atmospheric PCO2 (10 -3.5 atm) and the world-wide average riverwater chemistry plot is close to the Na ·Ca feldspar-calcite-riverwater equilibrium point. This result reasonably explains the similar estimated values of CO2 flux obtained by Meybeck (1987) and others and Gaillardet et al. (1999).The conditions for riverwater saturated with Na ·Ca feldspar and calcite were derived based on a dissolution kinetics-fluid flow coupling model and were expressed as functions of τ (residence time of groundwater) and A/M (A : surface area of mineral, M : mass of water).
著者
松野 太郎
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.100, no.6, pp.881-890, 1991-12-05 (Released:2009-11-12)
参考文献数
6
被引用文献数
1
著者
中埜 貴元 小荒井 衛 宇根 寛
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.124, no.2, pp.259-271, 2015-04-25 (Released:2015-05-14)
参考文献数
23
被引用文献数
5 8

Landform classification data are useful for assessing land liquefaction. Koarai et al. (2013) suggested a comprehensive risk assessment table for land liquefaction by combining 7.5-arc-second Japan engineering geomorphologic classification data (Wakamatsu and Matsuoka, 2009) with seismic intensity. The Geospatial Information Authority of Japan (2007) suggested a risk assessment standard for land liquefaction using land condition data produced by the Geospatial Information Authority of Japan. Our new hazard assessment standard for land liquefaction is based on land condition data and a risk assessment table produced by Koarai et al. (2013). Furthermore, a landform classification and hazard assessment standard of land liquefaction is suggested to create a simple land liquefaction hazard map. This information allows land liquefaction hazard to be assessed from land condition data or 7.5-arc-second Japan engineering geomorphologic classification data and to interconvert both land liquefaction hazard assessments.
著者
浅川 忠
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.708-714, 1993-12-05 (Released:2010-11-18)
参考文献数
18
著者
財城 真寿美 三上 岳彦 平野 淳平 Michael GROSSMAN 久保田 尚之 塚原 東吾
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.4, pp.447-455, 2018-08-25 (Released:2018-10-05)
参考文献数
14
被引用文献数
4

Past meteorological records are important for improving our understanding of past, present, and future climates. Imaging and digitization of historical paper-based instrumental meteorological records must be carried out before these records are lost to decay. This kind of activity called “data rescue” is now taking place at many institutions around the world. A data rescue project is underway to preserve Japanese instrumental meteorological records from the 19th century. These data were collected by foreign residents and visitors, Japanese scientists influenced by Dutch science, and by Japanese merchants. Recently, meteorological measurements taken at Mito from 1852 to 1868, and at Yokohama in 1872 and 1873 have been found. Based on instrumental records collected through this data rescue project, a warmer climate in the 1840s and 1850s around the South-eastern Kanto Region has been identified. Large year-to-year variations of winter temperatures have also been detected.
著者
藤井 理行
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.98, no.5, pp.535-561, 1989-10-25 (Released:2011-02-17)
参考文献数
53

In recent years it has become obvious that two large ice sheets in Antarctica and Greenland are most ideal medium for past some 100k year record of global climate and environment. Compared with deep-sea sediment, polar ice core has some following advantages as record medium for palaeo-environment.1) High resolution because of high accumulation rale, 2) High Accurcay because of inactive chemical at ice sheet surface, and3) Occulusion of air itself by the process of densification from firn to ice.Recent polar ice core studies have revealed 100 k-year cycle of climatic change and the synchronism between Northern and Southern Hemisphere. French and Soviet co-studies on Vostok ice core suggest that CO2 change have had an important climatic role during the late Pleistocene in amplifying the relatively weak orbital forcing. Thus ice core studies have provided fundamental information for the interpretation of glacial and interglacial climatic cycle. Furthermore, such studies on long term climatic changes basis on ice cores show the necessity of interdiciplinary interpretation on atmosphere-ocean-cryosphere climatic system and its relation to earth's orbital movement.Climatic cycle shorter than 100k-year shows regional characteristics. Hypsithermal, the warmest thousand years in Holocence appears in different ages; 8, 000-4, 100 years B. P. for Camp Century, Greenland core, 8, 000-4, 500 years B. P. for Byrd core, (9, 000)-5, 000 years B. P. for Mizuho core and 11, 000-8, 000 years B. P. for Dome-C core, Antarctica. So dose “little ice age”, the recent cold centuries. Polar ice cores reveal large volcanic eruption. Recent studies have suggested the climatic role of volcanic activities; The acidity of Byrd core indicates that a major volcanic event occurred for 150 years just when the transition period from the late glacial to the Holocence started.Thus polar ice core studies release valuable informations on palaeo-climate and environmont. However, further studies are requested for the detailed, quantitative and interdiciplinaly interpretation of 102-105 year climatic variation with high quality deep ice cores. Japanese Antarctic Dome Program at the top of Dronning Maud Land, Antarctica and European Greenland Ice Program (GRIP) are expepected to provide by-polar “standard” cores which will cover more than last climatic cycle.

1 0 0 0 OA 地名の話

著者
柳田 國男
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.24, no.10, pp.673-682, 1912-10-15 (Released:2010-10-13)
著者
海津 優
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.2, pp.275-283, 2020-04-25 (Released:2020-05-12)
参考文献数
11
被引用文献数
4

In 1880, Inoh Tadataka surveyed the meridian arc length corresponding to one degree of latitude difference. A record of calculations is contained in a handwritten manuscript titled “Sokuchidosetsu” or “On Meridian Arc Length Corresponding to One Degree.” The uncertainty of latitude for a short arc is dominant and is estimated to be about 0.42 minutes. This uncertainty is in accord with the rounding latitude at half a minute in many documents that refer to Inoh's work on coordinates. Some points were used for astronomical observations of latitude in two successive years. A comparison of those results suggests some bias in the results and a standard deviation around the mean of about 1.3 minutes. This is obviously much more than the uncertainty estimated from the scatter of one degree meridian arc length against the N–S component of a great circle connecting the ends of a route. Data sets of astronomical latitude observations surveyed independently help clarify the uncertainty associated with Inoh's latitude observations obtained from field surveys. The scatter of distance and latitude difference data around the linear trend suggests that the uncertainty of the N–S distance is about 7.3/10,000.
著者
鈴木 純子
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.129, no.2, pp.161-179, 2020-04-25 (Released:2020-05-12)
参考文献数
28
被引用文献数
3

The accomplishments of the survey projects of Inoh Tadataka in early 19th century Japan should not be evaluated merely from the visible results of his maps of the country. The latest surveying technologies and instruments, as well as his knowledge of the astronomical almanac, had a wide range of influences upon the surveying skills and astronomical knowledge of local surveyors and scholars. Inoh's Sokuryo-nikki (Survey diary) and records of local counterparts preserved in throughout Japan are reviewed and connections are evaluated. The records have been unearthed in recent years by historians editing regional histories and local history researchers. These investigations are important aspects of recent studies of Inoh's projects and supplement basic research of Otani (1917) and Hoyanagi (1974). During his journeys to survey Japan over seventeen years, Inoh kept a daily journal. It records some 12,000 people who attended or guided Inoh's team. However, his journal lacks details of connections among them. Local records contain extensive practical information concerning the project. Generally, officials of local lords or village officials accompanied the team of surveyors. They would learn on the job. According to their records and letters, some made and improved upon Inoh's surveying instruments. Others wanted to become students of Inoh and later attended private classes in Edo. Still others discussed calendrical calculations, trigonometric functions, and logarithm. Subsequently, some returned to their home regions and took charge of local surveys. As a result, we can recognize the wide range of influences the surveying project of Inoh Tadataka had.
著者
吉田 樹
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.2, pp.233-248, 2014-04-25 (Released:2014-05-16)
参考文献数
20
被引用文献数
4 4

This paper describes the history of regional and transport planning in the Tokyo Metropolitan Area, and considers the relationship between urban structure and transport planning. The network of major roads in Tokyo has been shaped by revitalization planning since the Great Kanto Earthquake of 1923 and the Pacific War. However, because of financial difficulties, some roads in the urban plan remain incomplete to this day. On the other hand, the Metropolitan Expressway network was planned around 1950, and about 940 thousand vehicles use the expressway every day. The railway companies around Tokyo, notably Japan National Railways, faced problems of overcrowding because the population of the Tokyo Metropolitan Area had increased and suburbs were created during the high economic growth period from the mid-1950s. Japan National Railways and Council for Transport Policy planned construction of new lines and the congestion rate of railways tended to decrease. Urban structure planning of Tokyo Metropolitan aimed to have a multipolar pattern during the tenures of former Tokyo Governors Shun-ichi SUZUKI and Yukio AOSHIMA. However, around a year after taking office, the former Tokyo Governor, Shintaro ISHIHARA, suggested the concept of a “ringed megalopolis,” which is invested in central Tokyo including subcenters for improving international competitiveness. Even with the different strategy for reconstructing an urban structure, road and railway planning has not changed. Transport planning in Tokyo metropolitan area has depended on urban planning that is designed not to interfere with the placement of urban functions, but follows and satisfies demand resulting from suburbanization. However, because an urban structure with a compact city has become more important, urban structure planning is required to be coordinated with transport planning.
著者
石田 瑞穂
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.96, no.4, pp.209-222, 1987-08-25 (Released:2009-11-12)
参考文献数
23

The occurrence of large earthquakes in the Kanto-Tokai (K-T) district has been interpreted by the interaction among the Philippine Sea (PHS), the Eurasian (EUR) and the Pacific (PAC) Plates the PHS and PAC plates underthrust beneath the EUR plate in this region. In order to understand the tectonic process taking place beneath the K-T region, the seismic activity, velocity structure and source mechanisms were studied by using the data from recently developed seismological observation networks. The double-planed structure of the intermediate-depth seismic zone was observed clearly beneath the Kanto districts, and the PHS plate underthrusting from the Sagami and Suruga troughs were clearly delineated by the high velocity and high seismic region. The distribution of pressure axes corroborated the results derived from the hypocentral distribution.
著者
鈴木 舜一
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.110, no.5, pp.734-743, 2001-10-25 (Released:2009-11-12)
参考文献数
36
被引用文献数
2
著者
M. SANTOSH 千秋 博紀
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.1, pp.100-114, 2011-02-25 (Released:2011-05-20)
参考文献数
50
被引用文献数
3 10

The history of supercontinents is briefly reviewed in relation to the origin of the Japanese Islands. The Japanese Islands formed part of the S. China Block, which was a part of supercontinent Rodinia at 1.0 Ga. Rodinia was rifted at 600 Ma, separating S. China Block, N. America, Australia and other continents, to generate the Proto-Pacific Ocean in between. On the other hand, the Hida and Oki islands belong to the N. China Block, which has much longer history than the S. China Block, extending back to 1.9-2.0 Ga with minor older rocks dating back to 3.8 Ga. The 1.8-2.0 Ga high-grade gneiss in the Hida and Oki belts may be part of the 1.8-1.9 Ga Nuna/Columbia supercontinent within which N. China-Japan occurred at the NE corner, as judged from key parallel belts of 1.8-1.9 Ga in N. China. The position of Japan at 1.0 Ga within Rodinia was at the center together with S. China and western margin of N. China. The oldest fossiliferous rocks in Japan may extend back to the Early Cambrian to Ediacaran formed during the rifting of Rodinia directly after Neoproterozoic snowball Earth. Initiation of subduction began ca. 520 Ma, and evolved through five Pacific-type orogenies along the southern margin of S. China. On the other hand, the Hida and Oki belts suffered the Triassic collision orogeny at 230-240 Ma, involving platform sediments up to the Carboniferous age. The final tectonic emplacement above the Jurassic accretionary complex may be related to the extensional event during the opening of the Japan Sea in the Miocene.
著者
兼岡 一郎
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.117, no.3, pp.668-673, 2008-06-25 (Released:2010-05-14)
参考文献数
10

Based on radiogenic isotopes, we can obtain information about the Earth related to time. Radiometric dating is a typical example. Due to the advanced development of current analytical techniques, radiometric ages covering the Earth's entire history can be obtained with an error of less than 1%, even for a mineral crystal. However, there still remain problems to be clarified including the reliability of decay constants and the meanings of value obtained. In another approach, an isotope ratio including a radiogenic isotope can be used to clarify the evolution of the Earth. By applying multiple isotope systematics for typical volcanic rocks such as Mid-oceanic ridge basalts (MORBs) and oceanic island basalts (OIBs), we conjecture the chemical state of the Earth's interior such as the degree of chemical fractionation and degassing. As an additional material used for clarifying the Earth's deep interior, I demonstrate the significance of kimberlites which might reflect the state of the Earth's deep interior more directly than OIBs.
著者
岡部 篤行
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.117, no.2, pp.312-323, 2008-04-25 (Released:2010-06-02)
参考文献数
33
被引用文献数
3 3

This paper reports the history of GIS developments in the 1970s and 1980s in Japan. The paper outlines ten GIS development projects: Small Area Information Systems, UIS-I, Geographic Information Processing System and Overlay Mapping Technique, Computer Graphic Systems for City Planning, ISLAND, TUMSY, Local Government GIS, Geographical Information Processing, TOGIS, and UIS-II.