巻号一覧
46 巻, 12 号
選択された号の論文の6件中1～6を表示しています
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G. K. Mukherjee, L. Carlo1994 年 46 巻 12 号 p. 1029-1041
発行日: 1994/12/20
公開日: 2007/04/03
ジャーナル フリーNightglow measurements of 630.0 nm emission line by high resolution tilting photometer have been compared with simultaneous Faraday rotation measurements of the ionosphere's total electron content (TEC) from ETS-II satellite (-130°E) at a low latitude station, KOLHAPUR (Geog. lat. 16.8°N, long. 74.2°E, dip lat. 10.6°N) in India. The preliminary observational data are presented and discussed for seven nights during March, 1989 and April, 1990. The comparative study shows that in general the airglow enhancements are associated with the night time enhancement in TEC. The airglow enhancement due to downward motion of the F layer during pre-dawn hours does not correlate with TEC fluctuations. Further, the time rate of change of content has been used to obtain rough estimate of the nightglow intensity level at the station. On comparisons 630 nm emission intensities computed from TEC values and those predicted by MSIS-86 (Hedin, 1987) and FAIM (Anderson et al., 1989) models show an accepted level of agreement. Results focus the coupling between airglow producing irregularities and TEC at low latitude ionosphere.抄録全体を表示PDF形式でダウンロード (27504K) -
Chihiro Kaito, Seiji Kimura, Kazuhiko Kamei, Yoshio Saito, Chiyoe Koik ...1994 年 46 巻 12 号 p. 1043-1050
発行日: 1994/12/20
公開日: 2007/04/03
ジャーナル フリーA recently developed experimental method to produce a compound by the use of reaction between thin film and ultrafine particles has been used for MgAl2O4 spinel formation. In the case of reaction between Mg particles and A1203 film, MgO and MgAl2O4 phases were produced by heating above 600°C. In the case of that between Al particles and MgO film, Al2O3 and MgAl2O4 were produced by heating above 600°C. The growth of the spinel phase at low temperature in the present systems was discussed on the basis of Mg ion or atom diffusions.抄録全体を表示PDF形式でダウンロード (27631K) -
Akira Hayashida1994 年 46 巻 12 号 p. 1051-1066
発行日: 1994/12/20
公開日: 2007/04/03
ジャーナル フリーMagnetic measurements have been made on samples from the Kurami and the Saigo Groups in the Kakegawa area, central Japan. Thermal demagnetization experiments reveal that the Matsuba Siliceous Siltstone of the late Early Miocene age preserves two magnetic components, distributed between 150 and 350°C and between 350 and 550°C. The fold test suggests that the low temperature component was acquired after the formation of the syncline, and that the high temperature component is of primary origin. The tilt-corrected direction of the high temperature component shows no significant deflection from the expected direction. Along with the Tomikusa and the Nohi-Yatsuo areas in the north, the Kakegawa area is suggested to have not significantly rotated since 16 Ma, while the clockwise rotation of Southwest Japan occurred at about 15 Ma. The bend of the MTL and the Pre-Neogene basement terranes can be attributed to the relative motion between Southwest Japan and the central part of the Honshu Island in the Miocene.抄録全体を表示PDF形式でダウンロード (43841K) -
Antony White, Graham Heinson1994 年 46 巻 12 号 p. 1067-1081
発行日: 1994/12/20
公開日: 2007/04/03
ジャーナル フリーGeomagnetic field measurements have been made at three new seafloor locations off the coast of southern Australia, to extend a magnetometer array deployed by White and Polatayko (1978). Geomagnetic depth sounding (GDS) and vertical gradient sounding (VGS) estimates provide a measure of both the TE and TM mode response of the continent-ocean boundary, which is relatively two-dimensional (2D) over hundreds of kilometres. The seafloor data from the continental shelf, mid-continental slope and at the edge of the abyssal plain show a strong geomagnetic coast effect which can largely be accounted for by the sea-water and a thick wedge of sediments in a rifted marginal basin on the continental shelf. A 2D inversion of the GDS and VGS estimates to determine the sub-seafloor conductivity structure suggests that (a) the oceanic crust and continental crust have conductivities of 0.05 and 0.005 S·m-1 respectively to a depth of 10 km, (b) the upper mantle above 140 km has conductivity 0.01-0.003 S·m-1, (c) the upper mantle between 140 and 390 km has conductivity less than 0.003 S·m-1, and (d) the lower mantle below 390 km has conductivity less than 0.3 S·m-1. No distinct boundary between oceanic and continental lithosphere conductivity can be discerned. The conductivity structure beneath the coastline of southern Australia is somewhat less conductive than the preferred model of Kellett et al.(1991) for southeastern Australia.抄録全体を表示PDF形式でダウンロード (44439K) -
Kiyoshi Fuji-ta, Satoru Yamaguchi, Kouji Kashihara, Takeo Ichikita, Ka ...1994 年 46 巻 12 号 p. 1083-1094
発行日: 1994/12/20
公開日: 2007/04/03
ジャーナル フリーExtremely Low Frequency (ELF) and Very Low Frequency (VLF) Magnetotelluric soundings were conducted at fourteen sites on the Oki-Dogo Island in the Japan sea. The Oki-Dogo Island which was formed during the Miocene volcanic activity, mainly consists of volcanic and metamorphic rocks. Electrical resistivity structures revealed by the magnetotelluric (MT) method well coincide with the classifications of the surface geology. The magnetotelluric investigation of the island also suggests that a clear resistivity contrast exists between the eastern and western parts of the island within a few kilometers in depth. In the western part of the island, a relatively high conductive layer of less than 20 ohm-m is detected at a depth of 200 m. This layer is interpreted as being a “water-aquifer”. In the eastern part of the island, a relatively resistive layer exists from the surface to 2 km in depth and this resistive layer is thought to relate to past volcanic activities. The resistivity contrast is also confirmed by the results of Schlumberger resistivity soundings.抄録全体を表示PDF形式でダウンロード (27012K) -
Seismo-Magnetic Studies between Dokurcun and Abant Area along the North Anatolian Fault Zone, TurkeyN. Orbay, O. Gündogdu, D. Kolçak, Z. Düzgit, A. M. Is ...1994 年 46 巻 12 号 p. 1095-1107
発行日: 1994/12/20
公開日: 2007/04/03
ジャーナル フリーSince 1985, magnetic measurements have been conducted between Dokurcun and Abant pilot area of Turkish-German Earthquake Research Project which is located on the western part of the North Anatolian Fault Zone. A total of 28 magnetic observation stations have been established as repeated measurements points, including a base station in Cakillar. In this study, the time differentials were obtained from the measurements taken during the time periods of April-October 1985, June-October 1986 and June 1987. When the local field variations between the successive periods were compared it is clearly seen that the intensity of the anomaly around the Dokurcun (DOK) decreased from +20 nT to -2 nT. These changes could be related with the earthquake of magnitude 2.2 (June, 1985) occurred north of Dokurcun. The other anomalies were also changed related with the epicenter distribution which are moved toward to the west from April 1985 to June 1987.抄録全体を表示PDF形式でダウンロード (28377K)
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