Ice-Wedge Cracks, Garry Island, Northwest Territories
Ice-Wedge Cracks, Garry Island, Northwest Territories
复制标题
西北地区加里岛的冰楔裂缝
DOI：
--
复制
发表时间：
1974
期刊：
影响因子：
--
通讯作者：
J. R. Mackay
中科院分区：
文献类型：
--
作者：
J. R. Mackay
对西北部加里岛冬季冰楔裂缝的观测，1967- 1973年期间的试验表明，开裂倾向于在1月中旬至3月中旬之间发生。平均而言，每年都有近40%的冰楔破裂。裂缝频率与积雪深度成反比。中等大小的冰楔，约1米宽，比更小或更大的冰楔更容易破裂，冰楔优先在中心附近破裂，并且经常年复一年地在几乎相同的地方破裂。 裂缝在表面平均约1厘米宽，向下逐渐变细，深度可能超过5米。 裂缝在春天部分闭合，然后形成新的冰细脉。多个楔形体提供的证据表明，裂缝有时可能在楔形体内而不是在地面上开始，因此裂缝向上和向下传播。
Observations made on winter ice-wedge cracks at Garry Island, N.W.T., for the 1967–73 period show that cracking tends to occur between mid-January and mid-March. On the average, nearly 40% of the ice wedges crack in any given year. The crack frequency varies inversely with snow depth. Medium sized ice wedges, about 1 m wide, crack more often than smaller or larger wedges, ice wedges crack preferentially near the center and often year after year at nearly the same place. The cracks average about 1 cm wide at the surface and taper downwards to depths which may exceed 5 m. The cracks partially close in spring before a new ice veinlet forms in them. Evidence provided by multiple wedges suggests that cracking may be initiated at times within the wedge rather than at the ground surface, and thus the cracks propagate both upwards and downwards.