-
Article type: Photogravure
1985 Volume 30 Issue 2 Pages
App3-
Published: July 01, 1985
Released on J-STAGE: January 15, 2018
JOURNAL
FREE ACCESS
-
Article type: Photogravure
1985 Volume 30 Issue 2 Pages
App4-
Published: July 01, 1985
Released on J-STAGE: January 15, 2018
JOURNAL
FREE ACCESS
-
Hiroshi MACHIDA, Fusao ARAI, Mitsugu MOMOSE
Article type: Article
1985 Volume 30 Issue 2 Pages
49-70
Published: July 01, 1985
Released on J-STAGE: January 15, 2018
JOURNAL
FREE ACCESS
The Aso-4 pyroclastic flow is one of the largest of late Pleistocene age in Japan covering extensive areas of Kyushu around the Aso caldera and western part of Honshu. We have recently discovered a distal ash which has very similar petrographic and chemical properties to the flow deposits at several localities of Japan, and is assumed to be an airfall part of the Aso-4 unit. The ash, named the Aso-4 ash, is a crystal-vitric fine-grained ash, consisting of rhyodacitic bubble-walled glass shards, and brown hornblende and orthopyroxene (bronzite) as mafic phenocrysts. Its identification is carried out by combined parameters ; refractive index of glass ranges 1.506-1.511, low refractive index of orthopyroxene (γ=1.699-1.701) and relatively high index of hornblende (n
2=1.687-1.688). In addition glass in the ash is characteristically rich in potassium. These properties are similar to those of the Aso-4 pyroclastic flows. It is suggested that the ash is a coignimbrite airfall deposit of fine-grained materials from the upper part of an eruption column formed at the same time as the Aso-4 flow. The ash mantles extensive areas from Kyushu to Hokkaido and is also recognized and identified in several piston cores from the Sea of Japan and the northwest Pacific Ocean. The fallout area of this ash is now known to attain approximately 4×10
6 km
2. It is striking that in the eastern part of Hokkaido, ca. 1700 km distant from the source, the ash with the thickness of 15 cm is well preserved immediately below the Kutcharo pyroclasitc flow deposits II/III. The bulk volume of this ash is estimated to be more than 400 km
3, possibly larger than that of the flow deposits. The stratigraphic position of this ash in standard sequence of South Kanto shows that it occurs after the Obaradai interstade (ca. 80 ka) and before the Misaki interstade (ca. 60 ka). Thus the Aso-4 ash provides a very important datum plane in late Pleistocene sequence in and around Japan.
View full abstract
-
Masaaki CHUREI
Article type: Article
1985 Volume 30 Issue 2 Pages
71-80
Published: July 01, 1985
Released on J-STAGE: January 15, 2018
JOURNAL
FREE ACCESS
For the purpose of investigating the properties of the long-period tremors of Aso volcano, Kyushu, an electro-magnetic long-period seismometer (T=10 sec, V=500, and 3 components) was installed at the Asosan Weather Station, from Oct. 23, 1982 to March 13, 1984. During the 2.5 years, the number of the tremors with amplitude of 2μ or larger amounted to 502, and each tremor had the wave train with 6-10 sec. in period. On the basis of the analysis of the particle motion of the tremor, it is found that the motion shows strong directivity, and the tremors seem to propagate from the E13±2°N direction. If the tremors, accordidg to the results of SASSA (1935), consist of body wave, the incidence angle of tremor is estimated as 54±3°. These results suggest that the tremors propagate from or through the region of 910±130 m in depth beneath the border between the Second and the Third crater of Nakadake. With respect to the maximum amplitude-frequency relation of the long-period tremors, the log-amplitude vs. log-frequency curves are non-linear, and bent downward at 2μ in amplitude (UD component). The m-value are obtained as ca. 5 in the amplitude smaller than 2μ, and ca. 8 in the larger one. The latter is conspicuously large compared with the values obtained in other volcanoes. This fact gives evidence that the long-period tremors have some limited magnitude.
View full abstract
-
K. Kaminuma, K. Shibuya, K. Niida
Article type: Abstract
1985 Volume 30 Issue 2 Pages
81-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
H. Fukuoka, M. Suzuki
Article type: Abstract
1985 Volume 30 Issue 2 Pages
81-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Kaminuma, M. Baba, S. Ueki, E. Koyama, J. Amino
Article type: Abstract
1985 Volume 30 Issue 2 Pages
81-82
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Suzuki, M. Shirao, H. Fukuoka
Article type: Abstract
1985 Volume 30 Issue 2 Pages
82-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
H. Kurasawa
Article type: Abstract
1985 Volume 30 Issue 2 Pages
82-83
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Nakamura
Article type: Abstract
1985 Volume 30 Issue 2 Pages
83-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
T. Fukuoka, F. Arai, F. Nishio
Article type: Abstract
1985 Volume 30 Issue 2 Pages
83-84
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Takayanagi
Article type: Abstract
1985 Volume 30 Issue 2 Pages
84-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Kasahara
Article type: Abstract
1985 Volume 30 Issue 2 Pages
84-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
S. Zashu, M. Ozima, O. Nitoh
Article type: Abstract
1985 Volume 30 Issue 2 Pages
85-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Kasahara, A. Yamamoto, H. Hamaguchi, N. Zana
Article type: Abstract
1985 Volume 30 Issue 2 Pages
85-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Kasahara, H. Hamaguchi, K. Sawasawa, N. Zana
Article type: Abstract
1985 Volume 30 Issue 2 Pages
85-86
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Suzuki-Kamata, Y. Shigaki, K. Yoshida, S. Aramaki
Article type: Abstract
1985 Volume 30 Issue 2 Pages
86-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
S. Nishimura, T. Ikeda, S. Suparka
Article type: Abstract
1985 Volume 30 Issue 2 Pages
86-87
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
Y. Sawada
Article type: Abstract
1985 Volume 30 Issue 2 Pages
87-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
Y. K. Kim, T. Yoshida
Article type: Abstract
1985 Volume 30 Issue 2 Pages
87-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
T. Kagiyama
Article type: Abstract
1985 Volume 30 Issue 2 Pages
87-88
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Aoki, T. Yoshida, S. Aramaki, H. Kurasawa
Article type: Abstract
1985 Volume 30 Issue 2 Pages
88-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
Y. Yokota
Article type: Abstract
1985 Volume 30 Issue 2 Pages
88-89
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
S. Nakada
Article type: Abstract
1985 Volume 30 Issue 2 Pages
89-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
A. Kubotera
Article type: Abstract
1985 Volume 30 Issue 2 Pages
89-90
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
J. Iriyama
Article type: Abstract
1985 Volume 30 Issue 2 Pages
90-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Sumita, K. Endo, T. Chiba
Article type: Abstract
1985 Volume 30 Issue 2 Pages
90-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Miyaji, G. A. Izett, C. W. Naeser, N. D. Naeser, P. A. M. Andriesse ...
Article type: Abstract
1985 Volume 30 Issue 2 Pages
90-91
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
Y. Kato
Article type: Abstract
1985 Volume 30 Issue 2 Pages
91-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
T. Ui, S. Kawachi, V. D. Neall
Article type: Abstract
1985 Volume 30 Issue 2 Pages
91-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
E. Abe, S. Nishimura, K. Katsura
Article type: Abstract
1985 Volume 30 Issue 2 Pages
91-92
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
T. Ui, H. Glicken
Article type: Abstract
1985 Volume 30 Issue 2 Pages
92-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Ishihara, M. Iguchi, K. Kamo
Article type: Abstract
1985 Volume 30 Issue 2 Pages
92-93
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
H. Toda, K. Niida
Article type: Abstract
1985 Volume 30 Issue 2 Pages
93-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Hayashi, H. Sugiyama, T. Fujino
Article type: Abstract
1985 Volume 30 Issue 2 Pages
93-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
Y. Katsui, Y. Chimoto
Article type: Abstract
1985 Volume 30 Issue 2 Pages
94-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Churei
Article type: Abstract
1985 Volume 30 Issue 2 Pages
94-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
T. Suzuki, Y. Katsui
Article type: Abstract
1985 Volume 30 Issue 2 Pages
94-95
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
H. Ono
Article type: Abstract
1985 Volume 30 Issue 2 Pages
95-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Seino, H. Ito, T. Yokota
Article type: Abstract
1985 Volume 30 Issue 2 Pages
95-96
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Ono, K. Watanabe
Article type: Abstract
1985 Volume 30 Issue 2 Pages
96-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
H. Watanabe, T. Maekawa, A. Suzuki
Article type: Abstract
1985 Volume 30 Issue 2 Pages
96-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Kaneko, Y. Takaura, K. Minato
Article type: Abstract
1985 Volume 30 Issue 2 Pages
96-97
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
T. Abiko, Y. Takita, K. Haraguchi
Article type: Abstract
1985 Volume 30 Issue 2 Pages
97-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
K. Aoki, T. Yoshida, Y. Masuda
Article type: Abstract
1985 Volume 30 Issue 2 Pages
97-98
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
I. Yokoyama
Article type: Abstract
1985 Volume 30 Issue 2 Pages
98-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
M. Ogata, M. Yamaguchi
Article type: Abstract
1985 Volume 30 Issue 2 Pages
98-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
Y. Nishida, H. Watanabe, T. Maekawa, I. Yokoyama
Article type: Abstract
1985 Volume 30 Issue 2 Pages
98-99
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
J. Ossaka, J. Hirabayashi, T. Kondo, M. Tsuchide
Article type: Abstract
1985 Volume 30 Issue 2 Pages
99-
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS
-
H. Metsugi
Article type: Abstract
1985 Volume 30 Issue 2 Pages
99-100
Published: July 01, 1985
Released on J-STAGE: February 13, 2018
JOURNAL
FREE ACCESS