Surface velocity fluctuations for Glaciar Universidad, central Chile, between 1967 and 2015
Surface velocity fluctuations for Glaciar Universidad, central Chile, between 1967 and 2015
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DOI：
10.1017/jog.2016.73
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发表时间：
2016-07
影响因子：
3.4
通讯作者：
Ryan Wilson;S. Mernild;J. Malmros;C. Bravo;D. Carrion
中科院分区：
文献类型：
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作者：
Ryan Wilson;S. Mernild;J. Malmros;C. Bravo;D. Carrion
对于观测到的质量平衡记录很少的安第斯山脉，长期的冰川速度测量可能是评估冰川健康的有用工具。利用手动和自动功能跟踪技术应用于电晕，陆地卫星和ASTER卫星图像，本文介绍了冰川大学1967年至1969年，1985年和2015年之间的表面速度波动，最长的时间序列可用于安第斯山脉，巴塔哥尼亚以外。这一时间序列揭示了1967年至1987年期间主要冰川主干的表面速度增加（约90%），随后在1987年至2015年期间减速（约80%），2014年至2015年期间观察到的冰速度可能代表48 a的低点。由于表面速度的波动，冰川锋在1985年至1992年期间向前推进（累计变化为137 ± 14米），并在1996-98年和2004-08年期间再次以较小的幅度前进。虽然在20世纪40年代表现出可能的激增行为，冰川大学与附近冰川报告的冰川变化的同步性表明，这座冰川正在对气候趋势做出反应。如果上述情况属实，结果表明，自20世纪80年代末以来，冰川质量平衡状况越来越不利。
ABSTRACT For the Andes Cordillera, where observed mass-balance records are sparse, long-term glacier velocity measurements potentially represent a useful tool for assessing glacier health. Utilising manual and automatic feature-tracking techniques applied to Corona, Landsat and ASTER satellite imagery, this paper presents surface velocity fluctuations for Glaciar Universidad between 1967 and 1969, and 1985 and 2015, the longest such time series available for the Andes Cordillera, outside Patagonia. This time series reveals an increase in the surface velocities of the main glacier trunk between 1967 and 1987 (~90%) followed by a deceleration between 1987 and 2015 (~80%), with ice velocities observed between 2014 and 2015 possibly representing a 48 a low. In response to the surface velocity fluctuations, the glacier front advanced between 1985 and 1992 (cumulative change of 137 ± 14 m), and again to a lesser magnitude during the 1996–98 and 2004–08 periods. Although having exhibited possible surge behaviour during the 1940s, the synchrony of the glacier changes presented for Glaciar Universidad with those reported for nearby glaciers, suggests that this glacier is responding to climatic trends. If the above scenario is true, the results indicate a general pattern of increasingly negative glacier mass-balance conditions since the late 1980s.