著者

早川 由紀夫

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.107, no.3, pp.Plate1-Plate2, 1998-06-25 (Released:2009-11-12)

著者

白尾 元理 早川 由紀夫

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.104, no.4, pp.Plate1-Plate2, 1995-08-25 (Released:2009-11-12)

著者

早川 由紀夫 井村 隆介

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.36, no.1, pp.p25-35, 1991-04

被引用文献数

4

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The eruptive history of Aso volcano for the past 80,000 years is revealed by tephrochronology and loess-chronometry. Around the Aso caldera is a thick accumulation of loess, which is intercalated with numerous Aso tephra layers of limited dispersal as well as three widespread tephra layers of known age that are good marker horizons ; the Akahoya ash (6.3 ka), the Aira-Tn ash (22 ka), and the Aso-4 ignimbrite (70 ka). Loess-chronometry is based on the assumption that, in the Aso region, the accumulation rate of loess has been constant as 12 cm/ky from 80 ka to the present. Most of tephra layers after the caldera-forming Aso-4 eruption are composed of volcanic sand or scoria lapilli of basaltic andesite composition. However the 27 ka Kusasenri dacite (SiO_2 = 67%) pumice is a conspicuous exception. The large volume of 5.85 km^3 (bulk) and wide dispersal of this pumice suggests that it is a product of plinian eruption. From October 5 to the end of November 1989, the Nakadake crater of Aso volcano was in eruption. Ash was uninterruptedly emitted from a 500-1,000 m high eruption column coming out of the crater. The average discharge rate of ash was 5 × 10^7 kg/day. The total mass of ash discharged during the two months reached 3 × 10^9 kg. The penultimate eruption in recent history was June-August 1979, when 7.5 × 10^9 kg of ash was discharged. Outside the Aso caldera, the thickness of the 1989 ash is less than 1 cm. It is almost impossible to detect an old ash layer of thickness about 1 cm in a loess cross section, suggesting that sedimentary records 10 km away from a volcano are insufficient to reconstruct past eruptions smaller than 10^<10> kg. Eruptions smaller than 10^<10> kg can be determined only from proximal deposits. The history of eruptions of Aso volcano over the last few thousand years is tentatively determined from cross sections 2-4 km west of the Nakadake crater. After a 580-1,250 year dormant period, Aso volcano became active about 1,780 years ago. From then, small eruptions each with 10^9-10^<10> kg ash discharge have been repeated 48-88 times up to the present. The duration of each eruption was a few months, and the dormant interval between eruptions averaged 20-37 years.

著者

JOHNSON Michael Paul

出版者

北海道言語研究会

雑誌

北海道言語文化研究 (ISSN:18826296)

巻号頁・発行日

vol.13, pp.147-160, 2015-03-30

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This paper describes an ongoing study evaluating the motivational effect of graded readersand extensive reading on Japanese engineering students learning English as a Foreign Language (EFL).The study evaluates attitudes and motivational orientations towards graded readers following asemester-long reading class which required learners to read extensively and take online quizzes via theMoodle Reader Module. Motivational orientations were assessed using the Graded ReaderInstructional Materials Motivational Survey (GR-IMMS), a questionnaire comprised of adapted scalesfrom Keller’s (2010) Instructional Materials Motivational Survey (IMMS) and open-ended items.Results of 270 (n=270) completed surveys indicated that the majority of learners positively endorsedextensive reading and the online evaluation system, and that content features, genre and textcharacteristics influenced learners’ perception of texts. Each of the cognitive variables examined inthe GR-IMMS scales were also positively endorsed. The implications of these findings are discussedas they relate to Japanese engineering students learning EFL.

著者

小林 哲夫

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.30, no.1, pp.45-47, 1985-04-01

著者

小林 哲夫

出版者

日本地質学会

雑誌

地質学論集 (ISSN:03858545)

巻号頁・発行日

no.24, pp.93-107, 1984-11-30

被引用文献数

6

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Yufu-Tsurumi volcanoes are situated at the northeastern part of Kyushu island, Japan. Lavas and pyroclastic rocks ranging from the late Pliocene to the late Quaternary in age form the basemment of this area and are cut by many active faults bringing about the blocks tilted variously. Judging from the tephrochronology of the wide-spread tephra, it has been confirmed that both Yufu and Tsurumi volcanoes started their activities more than 35,000 years ago. Yufu-dake is a stratovolcano with several parasitic lava domes and lava flows. The latest eruption occurred ca. 2,000-1,500 years ago issued the Tsukahara pyrodastic flow, the Ikeshlro lava, the Yufu-dake summit lava, and the Yufu-dake ash. The Tsukahara pyroclastic flow deposit is oxidized under the high temperature condition and has secondary fumarolic pipes. The Tsukahara pyroclastic flow is judged to have been formed by the collapse of an ascending lava dome. Stratigraphic relation between the pyroclastic flow and the volcanic ash shows that the collapse of the lava dome happened repeatedly at least two times. The last ascending of lava formed the Ikeshiro lava dome accompanied with lava flow. Shortly after that, the Yufu dake summit lava was issued and formed a summit lava dome. All the activities mentioned above represent a single cycle of eruption ceased within a short period of time. Based on the documentary record, however, it is convinced that the fumarolic activity was continued until the time ca. 1,100 years ago. Tsurumi volcano is composed of highly dissected volcanic edifice and the younger parasitic volcanoes. Based on the tephrochronology of wide-spread tephra, the younger parasitic volcanoes other than the Tsurumi-dake summit lava are judged to have been formed during the period of time ranging from 22,000 to 6,300 years before present. Garan-dake, Uchi-yama, and Nanpeidai are all lava domes and Oninomi-yama alone is a scoria cone with basaltic lava flow. The Tsurumi-dake summit lava which filled up the summit crater and formed a summit lava dome flowed down southward and eastward. One of the lobes of lava flow dammed up the river resulting in the developemment of a volcanic fan formed from the tip of a lava flow. Judging from the distrbution pattern of historic sites on the fan and the descriptions in the ancient manuscripts, it is reasonably concluded that the lava was issued about 1,500-1,200 years ago. Most of the rocks in this area is hornblende andesite ordacite, but a complicated assemblage of phenocryst, namely the olivine-clinopyroxene-orthopyroxene-hornblende-biotite-quartz-plagioclase-Fe-Ti oxides is frequently found in the rocks of of these volcanoes.

著者

小林 哲夫

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.82, 1975-03-25

著者

小林哲夫

雑誌

文部省科学研究費自然災害特別研究, 計画研究「火山噴火に伴う乾燥粉体流 (火砕流等) の特質

巻号頁・発行日

pp.137-163, 1986

被引用文献数

4

著者

坪井 誠太郎 久野 久

出版者

日本地質学会

雑誌

地質學雜誌 (ISSN:00167630)

巻号頁・発行日

vol.40, no.477, pp.380-381, 1933-06

著者

久野 久

出版者

日本地質学会

雑誌

地質學雜誌 (ISSN:00167630)

巻号頁・発行日

vol.68, no.796, 1962-01-25

被引用文献数

1

著者

久野 久

出版者

日本地質学会

雑誌

地質學雜誌 (ISSN:00167630)

巻号頁・発行日

vol.40, no.477, pp.379-380, 1933-06

被引用文献数

1

著者

久野 久

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.13, no.3, pp.123-130, 1968-12-01

被引用文献数

1

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Andesitic and dacitic lavas form a certain kind of autobrecciated structure upon entering into the water instead of forming the pillow structure common in basaltic lavas. Such lavas consist of angular, polyhedral blocks ranging in size from a few meters to several centimeters in diameter cemented by comminuted fragments of the same material or by sediments. Matrix of palagonite is sometimes present. Individual blocks are compact and are often traversed by joints which divide them into still smaller polyhedral blocks. In blocks larger than 0.5m., which are usually angular in outline and sometimes spheroidal, closely spaced joints roughly perpendicular to the surface of the blocks are developed, indicating their quenching against the water. In the Pleistocene volcanoes of Izu Peninsula and Hakone, no such subaqueous autobrecciated lavas have been found even along the present sea coast. This fact implies that they have never been uplifted since the beginning of the Pleistocene or have been partly submerged because of the elevation of the sea level since the end of the glacial period.

著者

佐藤 信次

出版者

日本地質学会

雑誌

地質學雜誌 (ISSN:00167630)

巻号頁・発行日

vol.68, no.796, pp.50-52, 1962-01-25

被引用文献数

1

著者

立見 辰雄 菊池 徹 久野 久

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.66, no.1, pp.17-33, 1957

著者

久野 久

出版者

The Association of Japanese Geographers

雑誌

地理学評論 (ISSN:00167444)

巻号頁・発行日

vol.13, no.9, pp.836-845, 1937

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野外に於ける諸事實に基き,箱根火山體を横斷して第1圖に鎖線で示した位置に一つの構造線を推定し,之を"金時山-幕山構造線"と名附けた。<br> 箱根火山古期外輪山熔岩噴出期の中頃に,本構造線の西北部では東北側地塊が東南部では西南側地塊が夫々反對側地塊に對して隆起し,其の結果火山體は第3圖に示した如き外形を呈するに至つた。又此の運動に伴つて金時山・幕山等の火山體が構造線上に噴出した。<br> 金時山熔岩其の他此の運動後に流出した各種の熔岩は,當時の斜面上の凹所(沈降部)を選んで流下し之を填めた結果,火山の外形は再び比較的凹凸の少いものに變じた。<br> 本火山最後の活動を代表する中央火口丘群も,本構造線に沿ふた弱線を利用して噴出した(第1圖参照)。<br> 古期外輪山熔岩の活動に關係した寄生火山,岩脈等の分布區域は,本構造線の運動によつて沈降した區域と略〓一致して居る事も明かになつた。<br> 本構造線の運動方向は,丹那斷層竝に足柄層の構造と共に,現在本邦本州各地に生ずる地震斷層の運動方向と類似する點が多い。

著者

久野 久

出版者

一般社団法人 日本地質学会

雑誌

地質学雑誌 (ISSN:00167630)

巻号頁・発行日

vol.44, no.523, pp.262-284, 1937 (Released:2008-04-11)

参考文献数

1

被引用文献数

1 1

著者

久野 久

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.73, no.5, pp.279-280, 1964-10-30 (Released:2009-11-12)

被引用文献数

1

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Basalt magmas in Japan range in composition from tholeiite, passing through high-alumina basalt, to alkali basalt. Picrite basalt related to either of these three basalt magmas is scarcely represented. In Hawaii, both tholeiite and alkali basalt are closely associated with picrite basalt having bulk compositions intermediate between the ordinary basalt and peridotite. The Japanese basalt magmas are supposed to be produced by sudden release of stress attending the generation of the intermediate to deep-focus earthquakes. In such a case, there may be a certain limitation of the heat energy supply for melting the mantle peridotite ; only a few per cent of the peridotite would be melted to form the basalt magmas.The Hawaiian basalt magmas are supposed to be produced by the heat transfer due to convection current within the mantle. In such a case, there would be less limitation of the heat energy supply for melting ; a greater per cent of the peridotite would be melted, resulting in the production of picrite basalt magmas.

著者

久野 久

出版者

岩波書店

雑誌

科学 (ISSN:00227625)

巻号頁・発行日

vol.31, no.1, pp.13-17, 1961-01

著者

李 在炯 城間 政司 丹田 賢 梅橋 一充 長田 智和 谷口 祐治 名嘉村 盛和

出版者

FIT(電子情報通信学会・情報処理学会)運営委員会

雑誌

情報科学技術フォーラム講演論文集

巻号頁・発行日

vol.11, no.4, pp.197-202, 2012-09-04

著者

寒川 典昭 荒木 正夫 渡辺 輝彦

出版者

Japan Society of Civil Engineers

雑誌

土木学会論文集 (ISSN:02897806)

巻号頁・発行日

vol.1986, no.375, pp.133-141, 1986-11-20 (Released:2010-08-24)

参考文献数

12

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This paper discusses the uncertainty of the estimated population parameters in the hydrologic frequency analysis. Firstly, the changes of the distribution shape and the probable variate of a fixed recurrence interval are investigated using the observed hydrologic data. Next, when the population parameters of the normal distribution are regarded as the random variables, the method of estimation of the decrease degree of the uncertainty, which is measured by the entropy of the distribution in unknown expectation-known variance and unknown expectation-unknown variance, is developed in some detail. Besides, applying this method of estimation to the observed hydrologic data, the validity of this method is investigated. Finally, the possibility of the application of this method to the non-normal population is suggested briefly.