All issues
Volume 43 (1981)
- Issue 4 Pages 201-
- Issue 3 Pages 137-
- Issue 2 Pages 73-
- Issue 1 Pages 1-
Volume 43, Issue 1
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
-
Michiya SUZUKI, Kokusho SHA, Hideaki EBIHARA, Toshihiro AKIBA1981 Volume 43 Issue 1 Pages 1-8
Published: March 31, 1981
Released on J-STAGE: February 05, 2010
JOURNAL FREE ACCESSCustomarily, the falling velocity of a particular snowflake is measured directly from the time interval taken for it to fall through a given vertical distance, and the size of the snowflakes is examined on dyed filter paper separately. That is, the direct and simultaneous measurements of the size and falling velocity of aggregate snowflakes in the falling space cannot be performed outdoors.
In order to measure both at once, the following new technique has been developed. The moving snowflakes are photographed by two cameras (one camera measures the falling velocity, the other the size) against a dark background. The shutter speeds of the two cameras are set at 1/30 and 1/1000 second. Since both of them are operated simultaneously, two pictures for the same snowflakes are obtained. From the short streak in the picture with a slow shutter speed, the velocity is measured. From the camera with a faster shutter speed, the size and number of the snowflakes are obtained. These negative films are magnified by a factor of 1.5 by a slide projector. Thus, the size, falling velocity and mean concentration of falling snowflakes are measured simultaneously from each negative. This paper describes the effectiveness of this new method as demonstrated by outdoor experiments, and shows that the falling velocity depends upon the size and the concentration of snowflakes under calm conditions.View full abstractDownload PDF (934K) -
Akio TOUKAIRIN1981 Volume 43 Issue 1 Pages 9-13
Published: March 31, 1981
Released on J-STAGE: February 05, 2010
JOURNAL FREE ACCESSFresh-water ice develops in Lake Harutori (0.39 km2 area, 42°58'30“ N lat, 144°24'30” E long ) in Hokkaido every winter from December to April. Rapid thawing of an ice floe, 12 cm thick and 0.13 km2 in area, occurred within 33 hours starting from the morning of 5 April 1973. Mechanism of melting is discussed on the basis of observations of morphology of ice floe, internal structure, meteorological and limnological regimes.View full abstractDownload PDF (8423K) -
Masao Saeki, Ryuzo Wakabayashi, Shigeo Watanabe, Yoshio Ohzeki, Shohji ...1981 Volume 43 Issue 1 Pages 15-20
Published: March 31, 1981
Released on J-STAGE: February 05, 2010
JOURNAL FREE ACCESSDrop-off processes of stumps after cutting on the mountain slopes in the Naeba Mountains, south Niigata Prefecture, where seasonal snowpacks between 3 m and 5 m deep on the average, were followed during 8 years, regarding their work in controlling avalanches.
1. Stumps with a higher center of gravity, or in heigher height-to-diameter ratio fell in number from earlier years after cutting than those in lower ratio. Stumps started to fall in number at 6 years after clear cutting and they decreased to half in 9 years, resulted by their decaying and outrooting due to large snow pressure.
2. In general the total glide gap of inclined snowpacks in each winter increased with decreasing stump density in number. Ground avalanches occurred on the grass thick slopes where seedlings had been planted just after clear cutting, only when the stump densities decreased to about 100 stumps/ha afterwards. On the bushy uncontrolled slopes where no trees had been planted after clear cutting, no avalanches occurred dispite drop-off of the stump number and increase of snow glide gap. This is because a part of bushes grew to a greater size thereafter was enough to check release of avalanches.
3. No avalanches occurred on the slopes where some intensities of selection cuttings had been tried. While the larger parts of clear cut slopes were developing into avalanche tracks denuded of vegetation inclusive of stumps and newly planted seedlings. In order to regenerate mountain forests in such heavy snow areas, it is preferable to retain effective snow supporting stands by treatment like selection cuttings.View full abstractDownload PDF (915K) -
Masao Oshima, Hitoshi Narita, Nobuyoshi Yashima, Mamoru Ando, Hiroshi ...1981 Volume 43 Issue 1 Pages 21-28
Published: March 31, 1981
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSDownload PDF (8026K) -
Yataro Sekido1981 Volume 43 Issue 1 Pages 41-54
Published: March 31, 1981
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSDownload PDF (17903K) -
Prcsented at the 24th International Geographical Congress. Tokyo. September 1980Kou KUSUNOKI1981 Volume 43 Issue 1 Pages 55-61
Published: March 31, 1981
Released on J-STAGE: August 07, 2009
JOURNAL FREE ACCESSJapanese Antarctic Research Expedition (JARE) established Syowa Station on East Ongul Island in Lutzow-Holm Bay in January 1957 and an inland station Mizuho in July 1970. These two stations have been the bases for glaciological work of JARE in conjunction with the research at home laboratories. Field activities of JARE are divided into three periods: the exploratory period from 1957 to February 1969 which was terminated with a successful return trip from Syowa Station to the South Pole in the 1968-1969 field season; the second period from 1969 to 1978 is characterized with a systematic glaciological survey of Mizuho Plateau by oversnow traverses and station glaciology at Mizuho Station where ice core drillings were conducted; from 1978 a three-year programme (POLEX-South) is in progress to investigate the air-ice sheet-sea (ice) interactions. Major outcomes in these periods are described briefly with the discovery of meteorities (about 4, 000 specimens) near the Yamato Mountains and the Belgica Mountains. Glaciological research and meteorite research in the south Victoria Land are appended.View full abstractDownload PDF (953K)
- |<
- <
- 1
- >
- >|