Grounding-line basal melt rates determined using radar-derived internal stratigraphy
Grounding-line basal melt rates determined using radar-derived internal stratigraphy
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DOI：
10.3189/002214310792447842
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发表时间：
2010-01-01
影响因子：
3.4
通讯作者：
Conway, Howard
中科院分区：
文献类型：
--
作者：
Catania, Ginny;Hulbe, Christina;Conway, Howard
我们使用南极洲西普勒穹顶和罗斯福岛接地线上的穿冰雷达数据来测量这些地点冰架下融化的空间模式、规模和持续时间。接地线上的地层显示，在某些地方，由于次冰架底部融化，接地线上或略低于接地线的地方出现了大幅度的下翘曲。局部向下翘曲表明熔融是瞬变的；熔融速率或接地线位置在几百年内发生了变化，以产生所观察到的地层。在其他地方，没有与熔融有关的地层学特征保留下来。在一定程度上，次冰架融化量的不均匀是由于次陆架洞穴中的区域环流模式，但局部(约数十公里)融化模式的不均匀可能反映了基准线上冰架底部形状的微小差异。我们发现，所有相交的接地线最多已经存在了大约400年。
We use ice-penetrating radar data across grounding lines of Sip le Dome and Roosevelt Island, Antarctica, to measure the spatial pattern, magnitude and duration of sub-ice-shelf melting at these locations. Stratigraphic layers across the grounding line show, in places, a large-amplitude downwarp at, or slightly downstream of, the grounding line due to sub-ice-shelf basal melting. Localized downwarping indicates that melting is transient; melt rates, or the grounding line position, have changed within a few hundred years in order to produce the observed stratigraphy. Elsewhere, no melt-related stratigraphic signature is preserved. In part, heterogeneity in the amount of sub-ice-shelf melt is due to regional circulation patterns in the sub-shelf cavity, but local (on the order of tens of kilometers) heterogeneity in the melt pattern may reflect small differences in the shape of the ice-shelf base at the grounding line. We find that all of the grounding lines crossed have been in place for at most similar to 400 years.