High-precision dating and correlation of ice, marine and terrestrial sequences spanning Heinrich Event 3: testing mechanisms of interhemispheric change using New Zealand ancient kauri (Agathis australis)
High-precision dating and correlation of ice, marine and terrestrial sequences spanning Heinrich Event 3: testing mechanisms of interhemispheric change using New Zealand ancient kauri (Agathis australis)
复制标题
DOI：
10.1016/j.quascirev.2016.02.005
复制
发表时间：
2016-04
影响因子：
4
通讯作者：
C. Turney;J. Palmer;C. Ramsey;F. Adolphi;R. Muscheler;K. Hughen;R. Staff;Richard T. Jones;Z. Thomas;C. Fogwill;A. Hogg
中科院分区：
文献类型：
--
作者：
C. Turney;J. Palmer;C. Ramsey;F. Adolphi;R. Muscheler;K. Hughen;R. Staff;Richard T. Jones;Z. Thomas;C. Fogwill;A. Hogg
要有力地测试晚更新世(6万至11650年前)突然和极端变化的地理同步性假设，需要达到冰层、海洋和陆地序列往往缺乏的年代精度水平。在这里，我们报告了一个跨越2000年的双分解的新西兰Kauri(Agathis Australis)树轮序列，它保存了北大西洋海因里希事件3(HE3)和南半球南极最大同位素4(AIM4)期间大气放射性碳(14C)的记录。利用海相Cariaco盆地中的14C和格陵兰冰层中保存的10Be，Kauri14C序列使我们能够精确地比对这一时期的序列。在HE3期间，我们没有观察到大气和海洋14C记录的显著差异，这表明没有表层水域分层和大西洋子午线翻转环流(AMOC)的崩溃。相反，我们的结果支持了最近的证据，即至少在两千年的冰川时期，AOC被削弱了。我们的工作增加了越来越多的文献，证实海因里希事件不是静止冷却的原因，并表明AMOC的变化不是两个半球之间反相温度趋势的主要驱动因素。古Kauri中年代际分解的14C提供了一种强大的新的(和补充的)极地冰芯CH4对齐方法，用于测试突变和极端气候变化的假设。
Robustly testing hypotheses of geographic synchroneity of abrupt and extreme change during the late Pleistocene (60,000 to 11,650 years ago) requires a level of chronological precision often lacking in ice, marine and terrestrial sequences. Here we report a bidecadally-resolved New Zealand kauri (Agathis australis)tree-ring sequence spanning two millennia that preserves a record of atmospheric radiocarbon (14C) during ice-rafted debris event Heinrich Event 3 (HE3) in the North Atlantic and Antarctic Isotope Maximum 4 (AIM4) in the Southern Hemisphere. Using14C in the marine Cariaco Basin and10Be preserved in Greenland ice, the kauri14C sequence allows us to precisely align sequences across this period. We observe no significant difference between atmospheric and marine14C records during HE3, suggesting no stratification of surface waters and collapse in Atlantic Meridional Overturning Circulation (AMOC). Instead our results support recent evidence for a weakened AMOC across at least two millennia of the glacial period. Our work adds to a growing body of literature confirming that Heinrich events are not the cause of stadial cooling and suggests changes in the AMOC were not the primary driver of antiphase temperature trends between the hemispheres. Decadally-resolved14C in ancient kauri offers a powerful new (and complementary) approach to polar ice core CH4alignment for testing hypotheses of abrupt and extreme climate change.