EVIDENCE FOR GENERAL INSTABILITY OF PAST CLIMATE FROM A 250-KYR ICE-CORE RECORD
EVIDENCE FOR GENERAL INSTABILITY OF PAST CLIMATE FROM A 250-KYR ICE-CORE RECORD
复制标题
DOI：
10.1038/364218a0
复制
发表时间：
1993-07-15
期刊：
影响因子：
64.8
通讯作者：
BOND, G
中科院分区：
文献类型：
--
作者：
DANSGAARD, W;JOHNSEN, SJ;BOND, G
在格陵兰中部钻取的两个冰芯的最新结果显示，在末次冰期晚期，至少在区域范围内发生了巨大而突然的气候变化，这表明北大西洋地区的气候能够迅速自我重组，甚至可能在几十年内。在这里，我们提供了格陵兰冰芯项目顶峰冰芯全长的详细稳定同位素记录，根据计算的时间尺度，延长了过去250 kyr。我们发现，气候不稳定不仅限于末次冰期，而且似乎在末次间冰期（在一篇论文中进行了更全面的探讨）和之前的萨勒-荷尔斯泰因冰期旋回期间也有明显表现。这与全新世的极端稳定形成对比，表明最近的气候稳定可能是例外，而不是规律。最后一次间冰期似乎比深海SPECMAP记录所暗示的持续时间更长，这与其他陆地观测结果一致。我们认为，最后一次间冰期早期的气候不稳定可能推迟了美洲和欧亚大陆萨勒冰盖的融化，这可能是造成这种差异的原因。
RECENT results1,2 from two ice cores drilled in central Greenland have revealed large, abrupt climate changes of at least regional extent during the late stages of the last glaciation, suggesting that climate in the North Atlantic region is able to reorganize itself rapidly, perhaps even within a few decades. Here we present a detailed stable-isotope record for the full length of the Greenland Ice-core Project Summit ice core, extending over the past 250 kyr according to a calculated timescale. We find that climate instability was not confined to the last glaciation, but appears also to have been marked during the last interglacial (as explored more fully in a companion paper3) and during the previous Saale-Holstein glacial cycle. This is in contrast with the extreme stability of the Holocene, suggesting that recent climate stability may be the exception rather than the rule. The last interglacial seems to have lasted longer than is implied by the deep-sea SPECMAP record4, in agreement with other land-based observations5,6. We suggest that climate instability in the early part of the last interglacial may have delayed the melting of the Saalean ice sheets in America and Eurasia, perhaps accounting for this discrepancy.