All issues
Volume 56 (1994)
- Issue 4 Pages 315-
- Issue 3 Pages 207-
- Issue 2 Pages 109-
- Issue 1 Pages 3-
Volume 56, Issue 2
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Isao KAMIISHI, Kunio KAWADA1994 Volume 56 Issue 2 Pages 109-118
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSLaboratory study of gravity current was made to obtain information related to the dynamics of powder snow avalanche. The gravity current was created by flowing saline water on a slope immersed in the fresh water tank. The densimetric Froude number of the gravity current was so closer as about the same as the avalanche in the field. The front velocity, the height and the density variation of the gravity current were measured changing the initial density and volume of the saline water.
The major finding of this study are that 1) the front velocity is proportional to the 1/4th power of the intial volume of saline water and 1/2th power of initial density difference, and 2) the density difference of the current is proportional to the initial density and volume of saline water.View full abstractDownload PDF (5802K) -
Tatuo HASEMI, Kunihiko BABA1994 Volume 56 Issue 2 Pages 119-126
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSIn the Kanto Plain, local fronts are formed between relatively warm eastery onshore winds and cold north-westerly winds from inland. The local fronts observed initially in the Boso peninsula progress forward inland when the cyclones are well developed and the easterly wind is strong. Near the ground surface, north-westerly wind is converged to the western part of the Plain by orographic blocking of the mountainous region.
Wet snow falls in the west of the front and the condition for growth of snow accretion occurs. Big disasters of power lines by snow accretion occured in this region.View full abstractDownload PDF (5231K) -
Isao KAMIISHI, Norio HAYAKAWA, Kunio KAWADA, Kyoei CHIBA1994 Volume 56 Issue 2 Pages 127-136
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSAn avalanche blasting device, called as GAZ. EX, which detonates mixture of propane and oxygen, was installed on a slope of Ougenashi Mountain, Niigata Prefecture. Test firing of this GAZ. EX in the winter of 1992 produced a series of large-scaled avalanche. This paper analyzes the mechanism of avalanche release and scale of the released avalanches. In May 1993, pressure measurement on the snow layer at the time of firing the GAZ. EX, was undertaken and it was shown that the over pressure on the snow surface is equivalent to that due to a skier, enough to release an avalanche.View full abstractDownload PDF (7216K) -
Ken KOIZUMI, Renji NARUSE1994 Volume 56 Issue 2 Pages 137-144
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSExperiments were conducted in laboratory on the formation and development of water veins and channels in ice. Under the condition of 0.0°C, veins of about 0.2 mm in diameter were formed within two days at triple junctions between grains of polycrystalline ice, and, one week later, water flow through the veins was observed using dye tracers. Measurements of discharge rate through a narrow, drilled hole in ice were also carried out by supplying pure water of 0.0°C from the upper end of the hole. The hole was enlarged as a result of melting of ice due to the heat converted from the potential energy of flowing water. The hole diameter increased from 1.5 mm to 2.7 mm by the continuous flow of water for five hours. Based on these experimental results and theoretical calculations, we conclude that, at the early stage of the ablation season in a temperate glacier, veins are firstly formed at the bottom of a supraglacial pond or a waterfilled crevasse, and they develop to water channels of an order of 10 cm in diameter after one month. If the water temperature of the pond is slightly higher than 0°C due to the absorption of solar radiation, the growth rate of channels is considerably higher.View full abstractDownload PDF (8232K) -
Tatsuo SEKIGUCHI1994 Volume 56 Issue 2 Pages 145-157
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSIt is known that slopes where full-depth avalanches often occur have characteristic features, which have not yet been described in detail. The author defines an “avalanche furrow” as a steep furrow shape which resembles a scratched needle mark on aerial photographs. This study investigates morphological features of avalanche furrows and their relationship to full-depth avalanches by photo-interpretation and field surveys at sampled areas in Hokuriku District, Japan. It also investigates the distribution of avalanche furrows over the whole area of Japan by interpretation of 1:15000 scale color photographs. From this study, it is concluded that slopes with avalanche furrows have characteristics very similar to those of the slopes where full-depth avalanches have been reported to occur. Furthermore, it is shown that the general distribution of slopes where an avalanche furrow is seen corresponds to the heavy snow regions in Japan.View full abstractDownload PDF (6705K) -
Masataka SHIRAKASHI1994 Volume 56 Issue 2 Pages 159-167
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESS -
Yoshitaka KAWADA, Masaru HATTORI1994 Volume 56 Issue 2 Pages 169-179
Published: June 15, 1994
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESS
- |<
- <
- 1
- >
- >|