The Eem Stable Isotope Record along the GRIP Ice Core and Its Interpretation
The Eem Stable Isotope Record along the GRIP Ice Core and Its Interpretation
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GRIP冰芯的Eem稳定同位素记录及其解释
DOI：
10.1006/qres.1995.1013
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发表时间：
1995
影响因子：
2.3
通讯作者：
H. Tauber
中科院分区：
文献类型：
--
作者：
S. Johnsen;H. Clausen;W. Dansgaard;N. Gundestrup;C. Hammer;H. Tauber
格陵兰冰芯项目（GRIP）在格陵兰冰盖（Summit）的最顶部钻取了一个3029米长的深冰芯，几乎延伸到基岩，该项目是由欧洲科学基金会组织的一项国际欧洲联合努力。根据部分基于地层学方法和部分基于冰流模型的测年，冰芯可以追溯到25万年前。沿着整个岩芯的连续而详细的稳定同位素（δ 18 O）剖面描绘了格陵兰岛在最后两个冰期循环中的剧烈温度变化，包括在Eem/Sangamon间冰期期间的突然气候变化，这在其他地方被记录为温暖而稳定的时期。因此，对Eemian层的地层连续性进行了仔细检查。新的冰芯研究，包括云带观测，反卷积和频率分析，导致的结论是，在格陵兰岛的Eem间冰期的气候不稳定性建议可能是真实的，虽然没有确凿的证据。北大西洋洋流的纬向位移被认为是冰川气候不稳定的直接原因，而纵向位移可能是Eemian不稳定的直接原因。如果是这样的话，Eemian气候变化将在北极地区以外的地区受到很大的抑制，并且可能只有在高灵敏度和时间分辨率的沉积序列中才能识别。
Abstract A 3029-m-long deep ice core extending nearly to bedrock has been drilled at the very top of the Greenland ice sheet (Summit) by the Greenland Ice-core Project (GRIP), an international European joint effort organized by the European Science Foundation. The ice core reaches back to 250,000 yr B.P. according to dating based partly on stratigraphic methods and partly on ice-flow modeling. A continuous and detailed stable isotope (δ18O) profile along the entire core depicts dramatic temperature changes in Greenland through the last two glacial cycles, including abrupt climatic shifts during the Eem/Sangamon Interglaciation, which is elsewhere recorded as a warm and stable period. The stratigraphic continuity of the Eemian layers has therefore been scrutinized. New ice core studies, comprising cloudy band observations, deconvolution, and frequency analyses, lead to the conclusion that the climate instability suggested during the Eem Interglaciation in Greenland is likely to be real, though no conclusive evidence is available. Whereas latitudinal displacements of the North Atlantic Ocean current are considered the immediate cause of the glacial climate instability, longitudinal displacements may be the immediate cause of the Eemian instability. If so, the Eemian climate changes will be much subdued outside the Arctic region and will probably only be recognizable in sedimentary sequences of high sensitivity and temporal resolution.