Late Quaternary evolution of Reedy Glacier, Antarctica
Late Quaternary evolution of Reedy Glacier, Antarctica
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南极洲Reedy冰川晚第四纪演化
DOI：
10.1016/j.quascirev.2010.02.001
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发表时间：
2010
影响因子：
4
通讯作者：
G. Bromley
中科院分区：
文献类型：
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作者：
Claire Todd;J. Stone;H. Conway;B. Hall;G. Bromley
里德冰川边缘上方的新沉积物表明，末次冰期的最高冰平面比冰川口附近的当前冰平面高出数百米，并在冰川顶部汇合到比当前冰平面高出不到60米。暴露年龄的样品从五个站点沿着其边缘显示，Reedy冰川及其支流增厚异步之间17和7 kyr BP在石英山，位于中间沿着冰川，最大冰水平达到期间17-14 kyr BP。在更远的冰川上，冰面最近达到了最大高度：在卡洛普拉卡山，14.7-10.2 kyr BP;在米姆斯支线，9.1-7.7 kyr BP;在哈奇布拉夫斯，大约7 kyr BP。我们把这种时间海侵行为归因于两个不同的过程：在冰川口，在罗斯海海湾，地面冰的生长和随后的冰川消退引起了一波增厚，然后变薄传播到冰川。在晚冰期和全新世期间，东南极冰盖积雪增加，导致冰川头部短暂增厚。这项工作的一个重要结果是，冰碛物沉积沿着芦苇冰川在最后一个冰河时代不能相关重建一个单一的冰川最大纵向剖面。剖面在罗斯海冰消期变陡，13 kyr BP后石英山变薄，而上游变厚。在与美世冰流汇合处附近，7-8 kyr BP之前开始的快速变薄使Reedy冰川的水平降低到接近其现在的水平。在过去的1000年里，冰川变薄了不到20米。
Fresh deposits above the margins of Reedy Glacier show that maximum ice levels during the last glaciation were several hundred meters above present near the glacier mouth and converged to less than 60 m above the present-day surface at the head of the glacier. Exposure ages of samples from five sites along its margin show that Reedy Glacier and its tributaries thickened asynchronously between 17 and 7 kyr BP At the Quartz Hills, located midway along the glacier, maximum ice levels were reached during the period 17–14 kyr BP. Farther up-glacier the ice surface reached its maximum elevation more recently: 14.7–10.2 kyr BP at the Caloplaca Hills; 9.1–7.7 kyr BP at Mims Spur; and around 7 kyr BP at Hatcher Bluffs. We attribute this time-transgressive behavior to two different processes: At the glacier mouth, growth of grounded ice and subsequent deglaciation in the Ross Sea embayment caused a wave of thickening and then thinning to propagate up-glacier. During the Lateglacial and Holocene, increased snow accumulation on the East Antarctic Ice Sheet caused transient thickening at the head of the glacier. An important result of this work is that moraines deposited along Reedy Glacier during the last ice age cannot be correlated to reconstruct a single glacial maximum longitudinal profile. The profile steepened during deglaciation of the Ross Sea, thinning at the Quartz Hills after 13 kyr BP while thickening upstream. Near its confluence with Mercer Ice Stream, rapid thinning beginning prior to 7–8 kyr BP reduced the level of Reedy Glacier to close to its present level. Thinning over the past 1000 years has lowered the glacier by less than 20 m.
西南极洲 Siple Dome 晚更新世变薄的证据
影响因子：
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作者：
Price, S. F.;Conway, H.;Waddington, E. D.
通讯作者：
Waddington, E. D.