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| index | Vol. 47 | 1 | 2/3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | Japanese Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pentane isomers in fumarolic gases: An example from the Kakkonda geothermal area, Northeast Japan
Shun-ichiro Igari, Tatsuo Maekawa and Susumu Sakata
1996
vol. 47 (1), p. 1-4, 2 figs., 1 table.
Keywords: Kakkonda, pentane isomers, fumarolic gas
Abstract: Neopentane, isopentane and n-pentane in fumarolic gases from the Kakkonda geothermal area were analysed. The neopentane/isopentane and neopentane/n-pentane ratios of the samples are found to be similar to those from the Akita and Niigata oil fields, while lower than those of "dissolved-in-water" type gases in Japan. This indicates that relatively little decomposition of the hydrocarbons occurred afer generation in the fumaric gases.
Damage in the Kobe and Hanshin urban areas during the 1995 Hyogoken-nanbu earthquake, and relation to the Rokko active fault system
Toashikazu Yoshioka, Toashikazu Miyachi, Akira Sangawa, Koichi Shimokawa, Yasuo Awata, Kiyohide Mizuno, Koji Okumura, Ryusuke Imura, Eikichi Tsukuda and Noriko Matsuyama
1996
vol. 47 (1), p. 5-22, 12 figs., 1 table
Keywords: Hyogoken-Nanbu earthquake, damage, active fault, Rokko active fault system, Kobe, Hanshin area
Abstract : The 1995 Hyogoken-nanbu earthquake caused severe damage to numerous buildings and houses in the Kobe and Hanshin urban areas and in Awaji Island. The most intense damage in Kobe and Hanshin occurred in intermittent areas along a <2 km wide belt (not parallel to the nearby the Rokko active fault system) located between the Rokko Mountain s and Osaka Bay. Much of the damage appears to be controlled by topography. For example, most of the houses destroyed between Motoyama-nakamachiand Mori-minaminachi and in the areas surrounding Rokkomichi station were located on marshyland between alluvial fans or in shallow valleys that dissect old alluvial fans. By contrast, less-damaged houses and buildings in the area between Hanakumacho and the Minatogawa station were located on alluvial terraces.
@Surface ruptures in the damaged area along the faults of the Rokko active fault system was restricted to landslides and liquefaction. The geodetic and seismological data collected indicate the seismogenic fault in the Kobe area is deeper and smaller than the Nojima fault.
Applications of Diffrential Synthetic Apertue Radar Interferometry of the Earth Sciences: Potential for geothermal reservoir monitoring
Minoru Urai and Yasushi Yamaguchi
1996
vol. 47 (1), p. 23-31, 5 figs., 1 table.
Keywords: geothermal reservoir, monitoring, surface deformation, Synthetic Aperture Radar, differential interferometry, remote sensing.
Abstract : Differential Synthetic Aperture Radar (SAR) Interferometry can be used to detect deformetions of the earth's surface. Some of the types of deformations that can be detected, and their temporal and spatial scales are reviewed in this study. In particular, differential SAR interferometry may be used to detect deformation of the earth's surface induced by vapor production in geothermal system. It is concluded that effective monitoring of surface deformation associated with geothermal reservoirs requires longterm observation and use of short wavelength sensors such as C-band SAR.
Relationship between 13C contents of slgae and concentration of dissolved carbon dioxide: A model and evidence
Susumu Sakata
1996
vol. 47 (1), p. 33-39, 4 figs.
Keywords:13C contents, algae, dissolved CO2 concentration, 2-step model, cell growth rate
Abstract : This paper reviews recent advances in understanding the relationship between 13C contents of algae and the concentration of dissolved carbon dioxide. The results are particularly important for paleoclimatic and paleoceanographic research. According to the 2-step model proposed by Farquhar et al. (1982) for algae that obtain CO2 by passive diffusion, the overall isotope effect associated with photosynthesis(denoted as p) can be written as: p=f-(f-t)E/[CO2(aq)],where t and f are the isotope effects associated with mass transport and carbon fixation, respectively, and is the difference in concentration of intracellular and external CO2 a value that reflects the cell growth rate (Rau et al.,1992). This model predicts that 13C content of algae correlates with [CO2(aq)] in hyperbolic form,and that the relationship may change depending on factors that control the cell growth rate,such as the concentration of nutrients. Recent studies indicate that the model is applicable to field samples (water column as well as sediments)and laboratory cultures.
Distribution of recent benthic foraminiferal assemblages in the surface sediments of the Hyuganada area, off Kyushu and Shikoku, Japan
Kazumi Akimoto and Masayuki Torii
1996
vol. 47 (1), p. 41-59, 12 figs., 4 tables.
Kywords: benthic foraminifera, Hyuganada, oceanegraphic condition, foraminiferal assemblage, recent, southwest Japan
Abstract : The distribution of Recent benthic foraminiferal faunas is discucced with reference to diferent oceanographic conditions. Recent benthic foraminiferal assemblages from 33 sediment samples were obtained during the GH83-2 Cruise (Hyuganada area).
@Based on the Q-mode factor analysis of the distribution of benthic foraminifera from including 33 sediment samples, eight assemblages were recongnized, (1) Cibicidoides mediocris-Hanzawaia nipponica Assemblage representing the sublittoral zone (100-200m), (2) Cibicides refulgens-Elphidium crispum Assemblage is distributed within the coarse grained sediments below the surface water, (3) Uvigerina hispidocostata-Sphaeroidina compacta Assemblage is characterized in the upper part of the salinity minimum zone (water depth interval between ca.700m and1000m) near off ashizurimisaki, (4) Bolivina robusta-Bulimina marginata Assemblage is characterized in coastal waters(70-200m) off Nichinan City, (5) Bulimina marginata-Discorbinella convexa Assemblage is distributed in the surface waters of the Kuroshio Current, (6) Hoegulundina elegans-Evolvocassidulina brevis Assemblage is characteristic of the outer sublittoral and upper bathyal zone, (7) Gyroidinoides nipponicus Assemblage represents the salinity minimumzone (water depth interval between ca.400m and 700m) off Toimisaki, and (8) Sphaeroidina compacta-Uvigerina hispida Assemblage is indicative of the oxygen minimum zone below a water depth of 900m.
