著者
和知 剛
出版者
筑波大学
雑誌
筑波フォーラム (ISSN:03851850)
巻号頁・発行日
no.65, pp.16-20, 2003-06

Wachi, Tsuyoshi
著者
和知 剛
出版者
筑波大学
雑誌
筑波フォーラム (ISSN:03851850)
巻号頁・発行日
no.65, pp.16-20, 2003-06

Wachi, Tsuyoshi旧・図書館情報大学であるところの図書館情報専門学群は、筆者が今更書くまでも無く1921(大正10)年に開設された文部省図書館員養成所以来、図書館司書養成という大義名分をその名称・機構の変遷にかかわらず背負ってきた。 …
著者
和知 剛 土井 宣夫 越谷 信
出版者
特定非営利活動法人日本火山学会
雑誌
火山 (ISSN:04534360)
巻号頁・発行日
vol.42, no.1, pp.17-34, 1997-03-07
被引用文献数
5

The Akita-Komagatake, located in the central part of the Ou Back-Bone Range, northeast Japan, is a Quaternary volcano with two calderas. The tephra, younger than 13,500 y.B.P., erupted from this volcano, are stratigraphically divided into thirteen formations, namely AK-13 to AK-1 in ascending order, on the basis of buried soil and loess intercalated. The tephra consists of three types of lithologies: such coarse-grained essential materials as pumice and scoria (type 1), well-sorted black to brown sandy ash (type 2), and fine-grained ash frequently including accretionary lapilli (type 3). These lithologic types are resulted from different styles of volcanic eruption: Plinian to subplinian style eruption (type 1), vulcanian to phreatoplinian style eruption (type 2) and phreatoplinian style eruption (type 3). ^<14>C measurements on humic soil or woods just below or above the tephra reveal the tendency that the explosive eruptions at the Akita-Komagatake volcano occured during three stages; 13,500 to 11,600 y.B,P., 10,000 to 7,100 y.B.P. and 4,000 to 1,000 y.B.P. In the first stage, AK-13, main part of which is called the Koiwai Pumice, and AK-12, the Yanagisawa Pumice, were erupted. During the eruption of the Koiwai Pumice, the Obonai Pyroclasitic Flow Deposits was produced. The volumes of erupted materials for the tephra including the pyroclastic flow deposit are more than 0-6 km^3, and two calderas are thought to have been formed in this stage. In the second stage, AK-11 to AK-6 were erupted. AK-9, the Arasawa Pumice (newly named in this paper), and AK-8, the Horikiri Pumice, are dominated by pumice and scoria (lithologic type 1), and their volumes of erupted materials are more than 0.1 km^3. The volumes for other tephra in this stage is more than 0.046km^3. Through the second stage to the last stage, the volumes of erupted materials tend to become smaller than 0.046km^3.
著者
和知 剛
出版者
図書館情報学研究会
雑誌
図書館情報学研究 (ISSN:13473247)
巻号頁・発行日
no.3, pp.63-73, 2005-02