巻号一覧
36 巻 (2002)
- 4 号 p. 149-
- 3 号 p. 109-
- 2 号 p. 65-
- 1 号 p. 1-
36 巻, 3 号
選択された号の論文の4件中1～4を表示しています
- |<
- <
- 1
- >
- >|
報文
-
太田 充恒, 今井 登, 岡井 貴司, 遠藤 秀典, 川辺 禎久, 石井 武政, 田口 雄作, 上岡 晃2002 年 36 巻 3 号 p. 109-125
発行日: 2002/08/10
公開日: 2017/01/10
ジャーナル フリーWe have made environmental assessment of the southern area of Yamagata Basin using geochemical map. Fifty-seven stream sediments and 15 rock samples were collected, and 51 elements were analyzed. The study area is roughly divided into four areas by the characteristics of geochemical maps and REE patterns. Statistical analysis of chemical composition in each area reveals that their distribution patterns are strongly affected by geological setting. However, we found the distribution patterns of some elements (As, Mo, Sn, Sb, Hg and Pb) independent on geological setting. In Yamagata City, highly enrichment of Cr, Ni, Cu, Zn, Sn, Sb and Pb is found. The geochemical maps show that the chemical compositions of stream sediments represent those of small river basins (1-50 km2). We have examined how large the catchment area the stream sediment will represent. It is proved that the stream sediment satisfactorily represents the watershed on a wide scale of 1-400 km2.抄録全体を表示PDF形式でダウンロード (2384K) -
川村 秀久, 田脇 紳次, 松岡 信明, 長野 隆義, 百島 則幸, 大崎 進, 前田 米蔵2002 年 36 巻 3 号 p. 127-135
発行日: 2002/08/10
公開日: 2017/01/10
ジャーナル フリーWe measured the δ34S values of plant leaves and of water-soluble SO42- in soil collected on the islands of Kyushu and Okinawa, Japan, and clarified the pathways of sulfur from the atmosphere to the plant-soil system by comparing the δ34S values with those of atmospheric sulfur. Most of the water-soluble SO42- in the soil was considered to derive from atmospheric sulfur by dry and wet deposition and it was assumed that the amounts of sulfur by dry deposition would be comparable to those by wet deposition. The δ34S values of water-soluble SO42- in the soil differed from site to site. This was attributed to the variability of (1) the δ34S values of sulfur by dry and wet deposition and (2) the ratio of dry deposition to wet deposition at each site. The δ34S values of the plant leaves at sites other than the town of Kokonoe were fairly close to those of water-soluble SO42- in the soil, suggesting that the plants absorb sulfur mainly as watersoluble SO42- from the soil. On the other hand, the δ34S values of the plant leaves at Kokonoe were considerably lower than those of water-soluble SO42- in the soil and were close to those of atmospheric SO2. The plants at Kokonoe were considered to depend on atmospheric SO2 for sulfur, which is essential for their growth.抄録全体を表示PDF形式でダウンロード (940K)
2001年度日本地球化学会賞受賞記念論文
-
日下部 実2002 年 36 巻 3 号 p. 137-147
発行日: 2002/08/10
公開日: 2017/01/10
ジャーナル フリーThe sudden release of carbon dioxide gas (CO2) from Lake Nyos in 1986 resulted in the loss of 1,746 lives. A similar event killed 37 people at Lake Monoun in 1984. Geochemistry of these gassy lakes in Cameroon has shown that carbon dioxide gas was accumulated in the deep layer of the lakes prior to the gas explosion. Carbon and helium isotopic ratios of dissolved gases indicate that the carbon dioxide was of mantle origin and carried up to the earth's surface by basaltic volcanism. Follow up geochemical surveys since the 1986 disaster suggested that CO2 leaked into the lakes in the form of CO2-rich spring and that CO2 concentration in the lakes is returning to dangerous levels. Thus, the sudden release of gas from these lakes may be repeated. The situation at Nyos and Monoun is unique in that we can make these potentially dangerous lakes safe by artificial removal of the dissolved gases. It can be stressed that the geochemistry of these lakes has given a basis for the degassing operation. Supported by the U. S. Office of Foreign Disaster Assistance (USAID-OFDA), a 203 m long degassing pipe was set up at Lake Nyos in January 2001. The degassing is based on a self-sustaining gas lift principle. With this apparatus, the dissolved gas is currently being removed at a rate approximately 9 times greater than the natural recharge at the bottom of the lake. More degassing systems need to be installed at Lakes Nyos and Monoun to make them safe in a reasonable period of time. Our efforts to this end are discussed briefly.抄録全体を表示PDF形式でダウンロード (1280K)
博士論文抄録
-
谷水 雅治2002 年 36 巻 3 号 p. 148-
発行日: 2002/08/10
公開日: 2017/01/10
ジャーナル フリーPDF形式でダウンロード (174K)
- |<
- <
- 1
- >
- >|