Full-scale avalanche experiments at Ryggfonn, Norway and studies on the dynamics of powder-snow avalanches

挪威 Ryggfonn 的全尺寸雪崩实验和粉雪雪崩动力学研究

基本信息

批准号：
02044005
负责人：
MAENO Norikazu
金额：
$ 5.5万
依托单位：
Institute of Low Temperature Science, Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

Among two types of snow avalanches the release and dynamic characteristics of wet snow avalanches are rather simple, but those of dry snow avalanches, especially of powder-snow avalanches, are complex and more detailed information is required. The present study was initiated in aiming to make various observations about internal structures and dynamic properties of powder-snow avalanches.Natural snow avalanches were observed at Shiai-dani in Kurobe Canyon by taking video-films and installing various sensors including impact pressure sensors and ultrasonic anemometer. One of the findings was the record of avalanche winds detected by a ultrasonic anemometer. The avalanche wind was observed to precede the avalanche body.Snow avalanches were artificially released at Ryggfon site in Norway. So far three avalanches were observed ; in one avalanche the mean running speed was 22 m/s, the volume and maximum depth of the debris were 20, 000 m^3 and 5 m respectively. The observation of size distribution of the constituent snow blocks showed that the larger ones tended to be accumulated at the front part of avalanches.Laboratory experiments of snow avalanches were also carried out by flowing numerous ice spheres (diameter 2.9 mm) in a 5-m long chute at temperatures from 0 to -30ﾟC. Measurements of velocities and densities of ice spheres showed significant inhomogeneity in the internal structure vertically as well as horizontally.

在两种类型的雪地雪崩中，湿雪雪崩的释放和动态特征很简单，但是干雪雪崩的散落和动态特征，尤其是粉末 - 烟雪崩的雪崩，这是复杂的，需要更详细的信息。本研究的开始是为了对粉末 - 弹药雪崩的内部结构和动态特性进行各种观察。在Kurobe Canyon的Shiai-Dani上观察到天然的雪雪崩，通过使用视频胶片并安装包括冲击压力传感器和超音速计的各种传感器，通过使用视频胶片和各种传感器。一个发现之一是超声波测量表检测到的雪崩风的记录。观察到雪崩风在雪崩体之前。Snow雪崩是在挪威的Ryggfon遗址人为释放的。到目前为止，观察到三个雪崩；在一个雪崩中，平均运行速度为22 m/s，碎屑的体积和最大深度分别为20,000 m^3和5 m。观察到构造雪块的尺寸分布表明，较大的雪块倾向于在雪崩的前部积累。还通过在温度从0到-30°C的温度下以5米长的溜槽在5米长的5米处将雪地雪崩的实验实验进行。冰球速度和密度的测量值在垂直和水平的内部结构上显示出明显的不均匀性。