Observation of rapid drainage system development by thermal erosion of ice wedges on Bylot island, Canadian Arctic Archipelago
Observation of rapid drainage system development by thermal erosion of ice wedges on Bylot island, Canadian Arctic Archipelago
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DOI：
10.1002/ppp.595
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发表时间：
2007-07-01
影响因子：
5
通讯作者：
Shur, Yuri
中科院分区：
文献类型：
--
作者：
Fortier, Daniel;Allard, Michel;Shur, Yuri
在拜洛特岛，一个新的排水系统迅速发展。一个750米长的沟系统在四年内被侵蚀。这一过程是由流入开放的冻裂的径流侵蚀冰楔形成的天坑开始的。这些天坑演变成了在冰楔网络和富含冰的永久冻土中开凿的地下隧道。随着隧道的拓宽，隧道的顶部出现了沉降和坍塌，并形成了露天冲沟。排水系统通常沿区域斜坡沿着形成最短线，但由于土块塌陷暂时阻碍了水流，导致排水系统出现一些偏差。在夏季，暴露于流水的退行性陡坎以最大5米/天的速度后退了15至50米。暴露于大气热量和太阳辐射的陡坎在四个夏季内后退了2.5 - 40米，平均为15.5米。这些斜坡在四年后几乎稳定下来，在最后一年的观察中，每年的后退速度只有几厘米。版权所有（c）2007约翰威利父子有限公司。
Rapid development of a new drainage system was observed on Bylot Island. A 750-m long gully system was eroded in four years. The process was initiated by the formation of sinkholes eroded in ice wedges by runoff flowing into open frost cracks. The sinkholes evolved into underground tunnels cut in the ice-wedge network and the ice-rich permafrost. Widening of tunnels was followed by subsidence and collapse of their roofs and the development of open gullies. The drainage generally developed as the shortest line along the regional slope with some deviations caused by collapse of blocks of soil which temporarily obstructed the water flow. Retrogressive scarps exposed to flowing water retreated at maximum rates of up to 5 m/day for a total of 15 to 50 m during the summer. Scarps exposed to atmospheric heat and solar radiation retreated between 2.5 and 40 m over four summers with a mean of 15.5 m. Such slopes had nearly stabilised after four years with a retreat rate of only a few centimetres per year in the last year of observation. Copyright (c) 2007 John Wiley & Sons, Ltd.