The 1987–88 surge of West Fork Glacier, Susitna Basin, Alaska, U.S.A.
The 1987–88 surge of West Fork Glacier, Susitna Basin, Alaska, U.S.A.
复制标题
1987-88 年美国阿拉斯加苏西特纳盆地西福克冰川的激增
DOI：
10.3189/s0022143000007334
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发表时间：
1994
影响因子：
3.4
通讯作者：
R. J. Benedict
中科院分区：
文献类型：
--
作者：
W. Harrison;K. Echelmeyer;E. Chacho;C. Raymond;R. J. Benedict
西福克冰川是阿拉斯加山脉苏西特纳盆地的一个温带冰川，1987年融化季节结束后不久，西福克冰川开始激增，并于1988年7月6日结束。1981年至1983年进行了平衡、海拔和速度的侦察测量。每天测量两个相距9公里的点的表面速度和冰川排水流的特征是在激增期间开始的，并持续到第二年。冰在浪涌期间的最大位移约为4公里;表面海拔的最大变化约为120米。从1988年2月12日开始进行详细观测，到最后一个月的涌浪进入复杂的终止阶段，速度几乎是恒定的，水的排放完全没有浑浊，这表明没有基底水从冰川中逸出。在终止阶段，两个观测点的速度几乎同时发生急剧变化;每次减速都伴随着高含沙量和高流量。这种行为与1982-83年在杂色冰川上观察到的情况相似。触发机制（与地表水输入和内部排水系统的中断有关）和快速运动的原因可能是相同的，即使在大小和质量平衡特性上有很大的差异。
Abstract A surge of West Fork Glacier, a temperate glacier in the Susitna Basin of the Alaska Range, began soon after the end of the 1987 melt season and terminated on 6 July 1988. Reconnaissance measurements of balance, elevation and speed had been made from 1981 to 1983. Daily measurements of surface speed at two points 9 km apart and of the characteristics of the stream draining the glacier were begun during the surge and continued through the following year. The maximum displacement of the ice during the surge was about 4 km; the maximum change in surface elevation was about 120 m. Between the time of the start of detailed observations on 12 February 1988 and the onset of a complex termination phase during the last month of the surge, the speed was almost constant, and the water discharge was totally free of turbidity, indicating that no basal water was escaping from the glacier. During the termination phase, sharp changes in speed occurred, almost simultaneously at the two observation sites; each deceleration event was accompanied by high sediment concentration and high water discharge. This behavior is similar to that observed on Variegated Glacier during its 1982-83 surge. The mechanism of triggering (related to surface water input and the disruption of the internal drainage system) and the cause of the fast motion were probably the same for both surges, even though there are substantial differences in size and mass-balance characteristics.