The 8.2-ka BP event in north-eastern North America: first combined oxygen and hydrogen isotopic data from peat in Newfoundland
The 8.2-ka BP event in north-eastern North America: first combined oxygen and hydrogen isotopic data from peat in Newfoundland
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DOI：
10.1002/jqs.2870
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发表时间：
2016-05-01
影响因子：
2.3
通讯作者：
Street-Perrott, F. A.
中科院分区：
文献类型：
--
作者：
Daley, T. J.;Barber, K. E.;Street-Perrott, F. A.
在全新世气候变化的陆地记录中寻找大气环流变化的直接证据仍然是一个根本性的挑战。在这里，我们提出了第一个结合稳定的氧和氢同位素古记录从泥炭地核心在纽芬兰，加拿大。泥炭藓纤维素样品从纽芬兰的Nordan池塘沼泽的岩芯中分离，并分析D值。与现有的O-18数据相结合，由此产生的D/O-18双情节直接与现有的测量现代（世纪末）的同位素组成的降水从GNIP站在新斯科舍省和拉布拉多，这意味着一个密切的关系之间的估计同位素组成的源水所使用的苔藓和源降水。我们使用的两个同位素记录之间的相对变化来检验的假设，即大气环流在千年后的8.2万年BP气候事件发生了变化。数据显示，二次复杂的同位素响应约200年（8250-8050年BP）后，主要的氧同位素事件，是广泛分布在北大西洋地区。这一次级事件的特点是氧和氢同位素记录的分歧，最有可能的解释是来自更遥远和更大陆的蒸汽源的降水水分的增加。版权所有（C）2016作者。《第四纪科学杂志》（Journal of Quaternary Science），由John Wiley & Sons Ltd出版。
Finding direct evidence for atmospheric circulation change in terrestrial records of Holocene climate variability remains a fundamental challenge. Here we present the first combined stable oxygen and hydrogen isotopic palaeorecord from a peatland core in Newfoundland, Canada. Sphagnum cellulose samples were isolated from a core from Nordan's Pond Bog, Newfoundland, and analysed for D values. Combined with existing O-18 data, the resulting D/O-18 bi-plot correlates directly with existing measurements of the modern (late 20th century) isotopic composition of precipitation from GNIP stations in Nova Scotia and Labrador, implying a close relationship between the estimated isotopic composition of source water used by the mosses and that of the source precipitation. We use the relative variations between the two isotope records to test the hypothesis that atmospheric circulation changed in the millennium following the 8.2-ka BP climate event. The data reveal a secondary complex isotopic response approximate to 200 years (8250-8050 a BP) after a primary oxygen isotopic event that is widespread in the north Atlantic region. This secondary event is characterized by a divergence in oxygen and hydrogen isotope records that can most plausibly be explained by the augmentation of precipitation moisture from a more distant and more continental vapour source. Copyright (C) 2016 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd.