Last glacial maximum climate based on cosmogenic 10Be exposure ages and glacier modeling for the head of Tashkurgan Valley, northwest Tibetan Plateau
Last glacial maximum climate based on cosmogenic 10Be exposure ages and glacier modeling for the head of Tashkurgan Valley, northwest Tibetan Plateau
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基于宇宙成因10Be暴露年龄和青藏高原西北塔什库尔干河谷谷头冰川模拟的末次盛冰期气候
DOI：
10.1016/j.quascirev.2013.09.004
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发表时间：
2013-11
影响因子：
4
通讯作者：
乔宝晋
中科院分区：
文献类型：
--
作者：
许向科;胡钢;乔宝晋
青藏高原西北部塔什库尔干河谷的顶部仍然缺乏对末次盛冰期（LGM）的时间和气候的充分了解。宇宙成因 10Be 暴露测年和冰川建模的最新进展为估计末次盛冰期气候条件提供了机会。在本文中，我们对冰碛进行了调查，并利用冰碛巨石上的 10Be 暴露测年法来限制末次盛冰期（位于塔什库尔干山谷顶部的库兹古冰川期）的发生时间。然后，我们使用耦合的质量平衡和冰流模型来量化受该地区绘制和测年的库兹贡冰川冰碛所限制的过去冰川范围的古气候。我们发现，库兹贡冰川期冰川终止于海拔 4100-4200 m asl，冰川期发生在 15-23 ka 期间或稍早，这与全球末次盛冰期的时间相对应。模拟的质量平衡表明，当前的平衡线高度 (ELA) 范围为 5150 至 5250 m asl，末次盛冰期 ELA 介于 4550 至 4600 m asl 之间，表明末次盛冰期间 ELA 降低了约 600 m。模型结果表明，考虑到降水量比今天减少了 30-70%，末次盛冰期期间塔什库尔干河谷顶部的气温比今天低 5-8°C。古气候估计与之前的研究基本一致，之前的研究表明青藏高原末次盛冰期的气候比今天更冷、更干燥。
Fully understanding the timing and climate of Last Glacial Maximum (LGM) is still lack in the head of the Tashkurgan Valley, northwest Tibetan Plateau (TP). The recent improvements in cosmogenic10Be exposure dating and glacier modeling present an opportunity to estimate the LGM climatic conditions. In the paper, we investigated the moraines and used the10Be exposure dating on the moraine boulders to constrain the timing of the LGM, the Kuzigun glacial stage in the head of the Tashkurgan Valley. Then, we used a coupled mass-balance and ice-flow model to quantify the paleoclimate from past glacier extents constrained by mapped and dated Kuzigun glacial moraines in the area. We showed that the glaciers terminated at an elevation of 4100–4200 m asl during the Kuzigun glacial stage and the glacial stage occurred during or slightly before 15–23 ka, corresponding to the timing of the global LGM. The modeled mass balances indicated that present-day equilibrium line altitude (ELA) ranges from 5150 to 5250 m asl, and LGM ELA is between 4550 and 4600 m asl in the area, suggesting an ELA lowering of ∼600 m during the LGM. Model results suggested that the temperature during the LGM in the head of the Tashkurgan Valley is 5–8 °C colder than today, considering a 30–70% reduction in precipitation compared to today. The paleoclimate estimates are generally consistence with previous studies that showed the LGM climate was colder and drier than today on the TP.
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影响因子：
4
作者：
J. Schaefer;Peter Oberholzer;Zhizhong Zhao;S. Ivy‐Ochs;R. Wieler;H. Baur;P. Kubik;C. Schlüchter-C.-Schlücht
通讯作者：
J. Schaefer;Peter Oberholzer;Zhizhong Zhao;S. Ivy‐Ochs;R. Wieler;H. Baur;P. Kubik;C. Schlüchter-C.-Schlücht
影响因子：
4
作者：
J. Spencer;L. Owen
通讯作者：
J. Spencer;L. Owen
DOI：
10.2307/1551118
发表时间：
1981-01
期刊：
Arctic and alpine research
影响因子：
--
作者：
R. Armstrong;W. Paterson
通讯作者：
R. Armstrong;W. Paterson
影响因子：
4.6
作者：
Yiqun Zheng;Yiqun Zheng;Gui Yu;Sumin Wang;Bin Xue;D. Q. Zhuo;Xin-Min Zeng;H. Liu
通讯作者：
Yiqun Zheng;Yiqun Zheng;Gui Yu;Sumin Wang;Bin Xue;D. Q. Zhuo;Xin-Min Zeng;H. Liu
影响因子：
4
作者：
R. Zech;M. Zech;P. Kubik;Krishna Kharki;W. Zech
通讯作者：
R. Zech;M. Zech;P. Kubik;Krishna Kharki;W. Zech