We present changes of the ice margin in Northwest Greenland at the Eastern part of the Nunatarssuaq Ice Cap (NIC) over six decades. The ice margin in this area terminates as a near-vertical ice cliff of between 9 and 33 m thickness. During the years 1954–1957 and in 1965 multi-disciplinary studies were performed. We digitise and orthorectify material, that is often difficult to access, in order to use the historical data as an absolute starting point of our change assessment. We compare the cliff morphology of the mid-1950s and the mid-1960s with various time-steps between 1985 and 2017. The studied ice margin remained remarkably constant with very subtle changes of changing sign: rather slow advance rates are reported from the 1950s and 1960s that accelerated until 1985 and were followed by a general retreat until 2012 and a subsequent advance until 2017. Thickness changes are negative throughout the entire time-period, however, different rates of thinning are shown and there is a positive relationship with air temperature anomalies. Compared to similar elevations on the adjacent Greenland ice sheet, we find significantly weaker thinning rates at the NIC.

中文翻译：

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重访红岩冰崖——格陵兰西北部努纳塔尔苏阿克地区 6 年的锋面、质量和面积变化

我们展示了 60 年来努纳塔苏瓦格冰盖 (NIC) 东部格陵兰岛西北部冰缘的变化。该区域的冰缘以接近垂直的冰崖终止，厚度在 9 至 33 m 之间。在 1954-1957 年和 1965 年进行了多学科研究。我们对通常难以访问的材料进行数字化和正射校正，以便将历史数据用作我们变更评估的绝对起点。我们将 1950 年代中期和 1960 年代中期的悬崖形态与 1985 年至 2017 年之间的不同时间步长进行比较。研究的冰缘保持显着不变，变化符号的变化非常微妙：据报道，从 1950 年代和 1960 年代开始，推进速度相当缓慢，直到 1985 年才加速，随后普遍退缩到 2012 年，随后又推进到 2017 年。在整个时间段内，厚度变化都是负的，但是，显示出不同的变薄率且与气温异常呈正相关。与相邻格陵兰冰盖上的类似海拔相比，我们发现 NIC 的变薄率明显较弱。