著者

杉浦 孜 杉崎 隆一 水谷 義彦 日下部 実

出版者

特定非営利活動法人日本火山学会

雑誌

火山. 第2集 (ISSN:04534360)

巻号頁・発行日

vol.25, no.4, pp.231-244, 1980-12-01

被引用文献数

2

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Ontake Volcano suddenly began to erupt on its south-western flank near the summit at 05^h20^m on Oct, 28, 1979, forming several new craters and ejecting large amounts of volcanic ash and steam. Up to that time, the volcano had been believed to be dormant, though there were weak geothermal activities at a part of the south-western flank of the volcano, Jigokudani. This paper reports some results obtained by preliminary examination of volcanic ashes, thermal waters and gases collected on and around Ontake Volcano during the early stage of eruptive activity. The volcanic ashes are homogeneous in chemical and mineralogical compositions, and similar in chemical composition to the pre-historic volcanic ashes. The ashes contain pyrite, anhydrite, cristobalite and clay minerals. The sulfur isotopic equilibrium temperature is estimated to be about 400℃ for pyrite-anhydrite pairs in the volcanic ashes. The estimated temperature is apparently too high for the temperature of phreatic explosion. The interpretation of this isotopic data remains unsettled. The thermal waters collected from the boiling pools in craters are enriched in D and 19^<O>. The isotopic enrichment is probably caused by evaporation of water at the surface of boiling pool. The hydrogen and oxygen isotopic data also suggest that spring waters issuing around Ontake Volcano are meteoric in origin. Nigorigo Hot Spring, about 4 km north-west of Ontake Volcano, showed significant increases in the concentrations of major dissolved chemical components soon after the eruption, but since then no significant change in chemical and isotopic composition has been observed

著者

杉崎 隆一 杉浦 孜 水谷 義彦 日下部 実

出版者

特定非営利活動法人日本火山学会

雑誌

火山. 第2集 (ISSN:04534360)

巻号頁・発行日

vol.25, no.2, pp.107-108, 1980-07-01

著者

杉崎 隆一

出版者

Japan Society of Engineering Geology

雑誌

応用地質 (ISSN:02867737)

巻号頁・発行日

vol.30, no.4, pp.213-224, 1989-12-25 (Released:2010-02-23)

参考文献数

29

著者

杉崎 隆一 志知 龍一

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.31, no.2, pp.195-206, 1978-07-31 (Released:2010-03-11)

参考文献数

21

被引用文献数

1 1

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The utility of the ratios of He/Ar and N2/Ar of fault gases as an earthquake precursor was discussed and examined. The ratio of helium to argon produced in the lithosphere remains rather constant (≅10) for the past several hundred million years irrespective of rock types. The ratio in the lithospheric air amounts to 105 times higher than that of the atmospheric air (5.7×10-4). The lithospheric air released by the formation of cracks and migrated by the stress in rocks prior to earthquakes, therefore, can be easily detected by means of the ratio. The N2/Ar ratio is also expected to be a useful parameter of a lithospheric air, because the ratio in natural gases and volcanic gases is generally higher than that of the atmospheric air. These ratios do not change a dilution process by other gases such as CH4 and CO2, and accordingly the ratios are more useful parameter of lithospheric air than a single element. The ratios of He/Ar and N2/Ar are gas-chromatographically measured without vacuum processes, temperature and pressure corrections and other complicated treatments.The result of successive measurement, since 1976, of the ratios in a fault at Inuyama Crustal Movement Observatory, Nagoya University, indicated that the ratios continuously fluctuated and the peak in the variation of the ratios of He/Ar and N2/Ar appeared prior to the most felt earthquakes in Nagoya (M≥4). The peaks of He/Ar preceeded those of N2/Ar for all events, which might be attributed to the difference in diffusion velocity of He and N2 through capillary cracks. The time lag of N2/Ar peak in case of the large earthquake is longer than that of the others. These features emerged in the variation of the ratios can possibly provide a practical mean of predicting earthquakes.

著者

永峰 康一郎 榊原 淳一 杉崎 隆一

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.42, no.2, pp.211-217, 1989-06-24 (Released:2010-03-11)

参考文献数

8

被引用文献数

2 1

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A computer-based system for automatic seismo-geochemical observations has been developed. At Hoshina hot spring, Nagano city, as a monitoring station, a personal computer regulates observation instruments such as gas chromatograph and water flow-meter, and it records the data on its floppy disks. In this study, the data transmission with a simplified telemetry system was improved. Through a public communication line and MNP modems, the data are sent to a personal computer in our laboratory. The modem enables us to transfer the data reliably without troubles caused by noise and phase delay, because it contains the function for correcting the error during correspondence. The simple BASIC program can be easily revised for expansion of measurement instruments. In view of cost, size and simplicity, this processing system is applicable for continuous on-site measurements for seismo-geochemistry.

著者

杉崎 隆一 杉浦 孜

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.39, no.1, pp.99-109, 1986-03-25 (Released:2010-11-17)

参考文献数

31

被引用文献数

1

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Remarkable anomalies in gas compositions were observed at a fumarole and three mineral springs before the Western Nagano Prefecture Earthquake, 1984. The epicentral distance are 9 km for the fumarole and 50 km, 71 km and 95 km for the springs, respectively. Deep seated gas emission induced by the compressive stress of the earth tide had been observed previously at the two mineral springs as the monitoring stations and at a lava lake in Hawaii. It is analogically inferred that the gas anomaly before the earthquake can be attributed to the variation in the emission rate of deep seated gas resulting from changes in pore pressure and magma-reservior volume, which are subjected to the tectonic stress that caused the earthquake. Another aspect is emissions of H2 gas at three mineral springs and gases from different sources at one spring. These indicate the formation of new cracks near monitoring stations and the permeation of groundwater into the cracks. The mechanical processes inferred from the present geochemical observation are compatible with those described by geophysical models based on fracturing experiments.

著者

忠隈 昌輝 高橋 正典 今村 勝徳 杉崎 隆一 八木 健 森本 政仁

出版者

一般社団法人電子情報通信学会

雑誌

電子情報通信学会技術研究報告. OFT, 光ファイバ応用技術 (ISSN:09135685)

巻号頁・発行日

vol.107, no.451, pp.1-4, 2008-01-17

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2007年9月16日〜20日にドイツ・ベルリンにて開催されたECOC2007の概要を報告する。約450件の報告の中から光ファイバ技術関連のトピックスを概説する

著者

八木 健 杉崎 隆一 荒井 慎一 相曽 景一 武笠 和則 小倉 邦男

出版者

一般社団法人電子情報通信学会

雑誌

電子情報通信学会技術研究報告. OFT, 光ファイバ応用技術 (ISSN:09135685)

巻号頁・発行日

vol.100, no.84, pp.1-6, 2000-05-18

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WDM伝送が急速な進歩を遂げている中, 光アンプ, 分散補償モジュール, 合分波モジュールあるいは波長変換モジュールなどの光を処理するためのデバイスが大きな進歩を遂げている.また, 新たなWDM用光源の検討も進められている.それらのデバイス・光機器のキーアイテムの一つとしてデバイス系光ファイバの開発にも力が注がれている.本論文では我々が開発している光ファイバー分散スロープ補償ファイバ, 非線形現象を回避するEDF, 高非線形性ファイバーの紹介を通して, デバイス系光ファイバの現況を考える.