Global sea-level contribution from the Patagonian Icefields since the Little Ice Age maximum
Global sea-level contribution from the Patagonian Icefields since the Little Ice Age maximum
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DOI：
10.1038/ngeo1122
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发表时间：
2011-05-01
影响因子：
18.3
通讯作者：
Cowley, A.
中科院分区：
文献类型：
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作者：
Glasser, N. F.;Harrison, S.;Cowley, A.
预计山地冰川和冰帽的融化将在世纪（1-）3对海平面上升起到重大作用，尽管这种作用的程度还没有完全确定。在过去的50年里，南美洲巴塔哥尼亚冰原的冰川被认为贡献了约10%的由山地冰川引起的海平面上升。然而，目前还不清楚巴塔哥尼亚最近的冰川衰退速度相对于过去几个世纪是否不寻常。在这里，我们重建这些冰川的衰退，利用遥感和实地测定的纵倾线和终碛位置。我们估计北巴塔哥尼亚冰原自公元1870年全新世晚期达到顶峰以来已经失去了103 +/- 20.7 km（3）的冰，而南巴塔哥尼亚冰原自公元1650年达到顶峰以来已经失去了503 +/- 101.1 km（3）的冰。这相当于自1870年以来，北方海平面贡献为0.0018 +/- 0.0004 mm yr（-1），自1650年以来，南方海平面贡献为0.0034 +/- 0.0007 mm yr（-1）。我们得出的百年海平面贡献率比过去50年的融化估计值低一个数量级（3），即使我们考虑到了纵倾线以上可能的变薄。我们的结论是，在二十世纪的巴塔哥尼亚冰原的融化速率和海平面的贡献显着增加。
The melting of mountain glaciers and ice caps is expected to contribute significantly to sea-level rise in the twenty-first century(1-)3, although the magnitude of this contribution is not fully constrained. Glaciers in the Patagonian Icefields of South America are thought to have contributed about 10% of the total sea-level rise attributable to mountain glaciers in the past 50 years(3). However, it is unclear whether recent rates of glacier recession in Patagonia are unusual relative to the past few centuries. Here we reconstruct the recession of these glaciers using remote sensing and field determinations of trimline and terminal moraine location. We estimate that the North Patagonian Icefield has lost 103 +/- 20.7 km(3) of ice since its late Holocene peak extent in AD 1870 and that the South Patagonian Icefield has lost 503 +/- 101.1 km(3) since its peak in AD 1650. This equates to a sea-level contribution of 0.0018 +/- 0.0004 mm yr(-1) since 1870 from the north and 0.0034 +/- 0.0007 mm yr(-1) since 1650 from the south. The centennial rates of sea-level contribution we derive are one order of magnitude lower than estimates of melting over the past 50 years(3), even when we account for possible thinning above the trimline. We conclude that the melt rate and sea-level contribution of the Patagonian Icefields increased markedly in the twentieth century.