Acceleration of thaw slump activity in glaciated landscapes of the Western Canadian Arctic
Acceleration of thaw slump activity in glaciated landscapes of the Western Canadian Arctic
复制标题
DOI：
10.1088/1748-9326/11/3/034025
复制
发表时间：
2016-03
影响因子：
6.7
通讯作者：
R. Segal;T. Lantz;S. Kokelj
中科院分区：
文献类型：
--
作者：
R. Segal;T. Lantz;S. Kokelj
气候变化正在增加热岩溶的频率和强度，但对区域气候和自然地理的影响仍然知之甚少。退化融化滑塌是热岩溶最具活力的形式之一，影响着加拿大西北部的许多冰川地形。在这项研究中，我们使用航空照片和卫星图像，以调查气候和景观因素对融化滑塌动态的影响。我们评估了滑塌的大小，密度和增长率在四个地区的冰丰富的地形与对比的气候和地形条件：杰西冰碛，Tuktoyaktuk冰碛地，蓝冰碛，皮尔高原。观察到的增加：（1）受滑塌影响的面积（+2至+407%），（2）平均滑塌面积（+0.31至+1.82公顷），（3）滑塌增长率（+169至+465平方米/年）表明，在加拿大北极西部富含冰的冰碛景观中，热岩溶活动正在迅速加速，滑塌已成为地貌变化的主要驱动力。不同地区滑塌特征的差异表明，滑塌的发展受到地形，地面冰条件和第四纪历史的强烈影响。所观察到的滑塌活动的增加与气温和降水量的增加同时发生，但四个区域之间滑塌活动的变化表明，降水量的增加是变化的重要驱动力。我们观察到，滑塌活动最迅速的加剧发生在最寒冷的环境（班克斯岛的杰西冰碛），这表明寒冷的永久冻土环境中的冰芯景观非常容易受到气候变化的影响。
Climate change is increasing the frequency and intensity of thermokarst, but the influences of regional climate and physiography remain poorly understood. Retrogressive thaw slumping is one of the most dynamic forms of thermokarst and affects many areas of glaciated terrain across northwestern Canada. In this study, we used airphotos and satellite imagery to investigate the influence of climate and landscape factors on thaw slump dynamics. We assessed slump size, density, and growth rates in four regions of ice-rich terrain with contrasting climate and physiographic conditions: the Jesse Moraine, the Tuktoyaktuk Coastlands, the Bluenose Moraine, and the Peel Plateau. Observed increases in: (1) the area impacted by slumps (+2 to +407%), (2) average slump sizes (+0.31 to +1.82 ha), and (3) slump growth rates (+169 to +465 m2 yr−1) showed that thermokarst activity is rapidly accelerating in ice-rich morainal landscapes in the western Canadian Arctic, where slumping has become a dominant driver of geomorphic change. Differences in slump characteristics among regions indicate that slump development is strongly influenced by topography, ground ice conditions, and Quaternary history. Observed increases in slump activity occurred in conjunction with increases in air temperature and precipitation, but variation in slump activity among the four regions suggests that increased precipitation has been an important driver of change. Our observation that the most rapid intensification of slump activity occurred in the coldest environment (the Jesse Moraine on Banks Island) indicates that ice-cored landscapes in cold permafrost environments are highly vulnerable to climate change.