著者

加藤完治 著

出版者

満洲移住協会

巻号頁・発行日

vol.前篇, 1939

著者

須藤 茂 阪口 圭一 松林 修 鎌田 浩毅 加藤 完 山本 隆志

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

巻号頁・発行日

vol.29, pp.S253-S265, 1984

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Temperature measurements of the lava of 1983 in Miyake-jima in the Ako district were started fifty days after the eruption and have been continued since then. The following three kinds of temperature data have been obtained (Fig. 2). 1. Temperatures at 20 cm depth along a graveled temporary road on the clinkery surface of the lava using mercury and alcohol thermometers. 2. Temperatures at 0.5 to 2.5 m depth in iron pipes inserted into the clinker layer using thermocouples and mercury thermometers. The pipe holes were distributed along the temporary road and at scattered stations on the surface of the lava. 3. We drilled a borehole (DH-1) which penetrates through 5.5 m-thick lava into the previous ground. Temperature was measured at 10 points in the hole using thermocouples. For comparison, similar measurements in the Awabe district were made in pipes with depths up to 2.5 m (Fig. 3). These pipes were buried in the holes dug into the massive part of the lava for electric poles. The temperature data at 20 cm depth and in the pipe holes (Figs. 5-10) indicate that isothermal surfaces in the clinker layer are very complicated. This complexity is explained by rising plumes of hot vapor irregularly present in the lava field. The vapor is produced by degassing process in the massive part of the lava and comes up through newly formed cooling joints. Once a cooling joint is formed, the temperature of the massive part of the lava around the joint fell rapidly because a gas plume effectively transports the heat from the massive part to the surface. But the rate of temperature decrease varies greatly from one station to another. New plumes were formed sporadically and the temperatures of the new plumes were much higher than the decreased temperatures of the older plumes. Some older plumes died out because degassing process ended or the joints were self sealed by sublimates. It is necessary to arrange a number of observation stations and to add stations timely in order to reveal a cooling history of aa lava like the lava of 1983 in Miyake-jima. Around a plume, a convection cell was identified in the clinker layer (Figs. 16-18), which is similar to a hydrothermal convection system usually found in geothermal areas. The change of the temperature-depth profile of DH-1 with time (Figs. 11, 12) clearly shows that the lava heated the underlying previous ground. The peak shape of the profile has become broader and the depth of the maximum temperature has steadily fallen. The change of the temperature-depth profile also suggests that the upper clinker layer prevented rainfall from effective cooling of the massive part of the lava for the first 250 days. During that time, raindrops were evaporated in the clinker layer and did not reach the massive part below the clinker layer. Difference of cooling rate between Awabe lava and Ako lava may be due to the difference of the thickness of the clinker layers (Figs. 15, 19).

著者

加藤 完 高橋 誠 吉川 清志

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.47-55, 1986-03-25 (Released:2010-11-17)

参考文献数

16

被引用文献数

2

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Weekly monitoring of radon concentration in soil gas in some active fault areas has been carried out using cellulose nitrate film as a part of earthquake prediction research. As the results of observation, we found increase of track density (tracks/cm2day) along the Median Tectonic Line (distance 100km) and the Matsushiro fault (_??_100km) since summer of 1982 and along the Ateta fault (_??_25km) since summer of 1983. We considered it as a precursor of the Western Nagano Prefecture Earthquake, 1984, by the reason that this increase just fit with the empirical formulas which relate the distance and apperance time of the precursory anomaly against the magnitude of an earthquake.At the same time, we found an annual variation of track density higher in summer and lower in winter. Supposing this annual variation being due to the seasonal variation of soil temperature, using uranium ore as source of random. As the result of experiment, it was clarified that track density increased with increased exposure temperature.

著者

加藤 完 高橋 誠 風早 康平 安藤 直行

出版者

特定非営利活動法人日本火山学会

雑誌

日本火山学会講演予稿集

巻号頁・発行日

vol.1989, no.1, 1989-04-06

著者

加藤 完治

出版者

日本地質学会

雑誌

日本地質学会学術大会講演要旨

巻号頁・発行日

vol.88, 1981-04-01

著者

加藤 完治

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, 1980-07-01