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Volume 36 (2002)
- Issue 4 Pages 149-
- Issue 3 Pages 109-
- Issue 2 Pages 65-
- Issue 1 Pages 1-
Volume 36, Issue 1
Displaying 1-5 of 5 articles from this issue
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Review
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Tomoaki OKUDA2002 Volume 36 Issue 1 Pages 1-14
Published: March 10, 2002
Released on J-STAGE: January 08, 2017
JOURNAL FREE ACCESSThis paper reviews some recent important works in environmental chemical studies of compound-specific stable carbon isotope analysis of polycyclic aromatic hydrocarbons (PAHs), and summarizes (i) analytical methods, (ii) isotopic fractionations in some environmental processes such as evaporation, photodegradation, and biodegradation, (iii) endmembers, (iv) environmental samples, and (v) future perspectives for measurement of δ13C of PAHs.View full abstractDownload PDF (1586K)
Original papers
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Kouji TSUSHIMA, Shingo UEDA, Norio OGURA2002 Volume 36 Issue 1 Pages 15-22
Published: March 10, 2002
Released on J-STAGE: January 08, 2017
JOURNAL FREE ACCESSThis study aimed to clarify the possible role of floodplains in biogeochemical nitrogen cycles based on dynamics of inorganic nitrogen species in groundwater. Samples collected from groundwater of the floodplain in the middle reach of the Tama River, Nagata district, were analyzed for dissolved oxygen, dissolved organic carbon, major ions, nitrous oxide and nitrogen stable isotope ratio of nitrate. There were some observed wells where the dissolved oxygen concentration in groundwater was kept low through the observation period. In groundwater with lower dissolved oxygen concentration, nitrate decreased to the detection limit mainly in the summer season. Furthermore, nitrous oxide decreased to below the atmospheric equilibrium concentration (〜10nM) in the season of nitrate decline. In aerobic groundwater, nitrate is the predominant inorganic nitrogen species and concentration of nitrous oxide is known to be higher than the atmospheric equilibrium. However, floodplain groundwater was sink for both nitrate and nitrous oxide. Thus this study proves that unconfined groundwater in floodplain can perform an important role as nitrogen sinks for material cycles in river catchments.View full abstractDownload PDF (861K) -
Hidehisa KAWAMURA, Shinji TAWAKI, Nobuaki MATSUOKA, Takayoshi NAGANO, ...2002 Volume 36 Issue 1 Pages 23-33
Published: March 10, 2002
Released on J-STAGE: January 08, 2017
JOURNAL FREE ACCESSThe δ34S values of atmospheric SO2, and of SO42- in aerosols and in bulk precipitation collected over Kyushu Island were measured, and the sulfur sources were identified by comparing the δ34S values with those of the sources. The δ34S values of SO2 were fairly close to those of SO2 emitted from local sulfur sources such as petroleum combustion or fumaroles, suggesting that the contribution of the local sources to the atmosphere is relatively large. The δ34Snss values of nss-SO42- in aerosols and in bulk precipitation showed seasonal variations with a maximum in winter. The high δ34Snss values observed in winter could not be explained only by an isotopic fractionation effect during the oxidation of SO2 to SO42-, suggesting that SO42- with high δ34S values must be present. It is considered that the desert soil SO42- and SO42- from coal combustion with high δ34S values are transported from continental Asia to Kyushu Island by the northwest seasonal winds in winter, so that the δ34Snss values become high in winter. The results indicate that there is strong possibility of long-range transport of SO42- from continental Asia to Kyushu Island.View full abstractDownload PDF (1136K) -
Yoshikazu KIKAWADA, Takao OI, Joyo OSSAKA2002 Volume 36 Issue 1 Pages 35-49
Published: March 10, 2002
Released on J-STAGE: January 08, 2017
JOURNAL FREE ACCESSLong-term changes in temperature, pH and major element chemistry during 1969 and 1999 were investigated for the three hot springs, Manza-Yubatake, Okumanza and Manza-Karabuki, in the Manza hot spring area located in the western foot of Kusatsu-Shirane volcano, Gunma, Japan. At Manza-Yubatake and Okumanza, water temperatures have been decreasing for at least these 60 years except occasionally small irregular changes probably accompanied by the change of volcanic activity of Kusatsu-Shirane volcano. The concentrations of dissolved components of Manza-Karabuki water have widely fluctuated obviously related with volcanic activities, while the water temperature has rarely been fluctuated. The waters of the three hot springs show similar ratios among the concentration of the analyzed dissolved components except calcium and sulfate ions, which are possibly controlled by the solubility of gypsum. The similarity of chemical composition and the highest concentration of dissolved species in the Manza-Karabuki waters indicate that Manza-Yubatake and Okumanza waters are formed by the mixing between local meteoric water and the Manza-Karabuki water, which has the closest chemical composition to the primitive hydrothermal fluids related to the volcanic activity in the Manza area.View full abstractDownload PDF (1433K)
The Geochemical Society of Japan Award for Young Researchers
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Urumu TSUNOGAI2002 Volume 36 Issue 1 Pages 51-63
Published: March 10, 2002
Released on J-STAGE: January 08, 2017
JOURNAL FREE ACCESSThis paper summarizes stable carbon isotopic studies of hydrocarbons, especially methane, in seafloor venting hydrothermal and cold seep fluids, and their effluent methane-enriched plume in water column. Through highly sensitive isotopic analysis using CF-IRMS, we have discussed origin and/or behavior of hydrocarbons in each system. Major results are as follows: (i) methane in cold seep fluids around Japanese islands mostly microbial origin, (ii) methane emitted from cold seep fluids mostly oxidized anaerobically within sediments just before they emitted into ocean, (iii) methane in hydrothermal plume oxidized aerobically in some extent in the water column. Besides, methane flux and heat flux can be calculated for a methane-enriched fluid venting area from δ13C distribution of methane in hydrothermal plume, by using kinetic isotope fractionation which occurs during partial destruction of methane in water column as an indicator to estimate magnitude of the partial destruction. Similar approach could be also applicable to study origin and behavior of reactive trace components in atmosphere, such as nonmethane hydrocarbons and CO. Preliminary results of such studies are also presented.View full abstractDownload PDF (1522K)
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