Universidad Complutense de Madrid, 28040 Madrid, Spain.
Instituto de Geociencias, CSIC-UCM, 28040 Madrid, Spain.
Nat Commun. 2017 Jul 6;8:16008. doi: 10.1038/ncomms16008.
Palaeo data suggest that Greenland must have been largely ice free during Marine Isotope Stage 11 (MIS-11). However, regional summer insolation anomalies were modest during this time compared to MIS-5e, when the Greenland ice sheet likely lost less volume. Thus it remains unclear how such conditions led to an almost complete disappearance of the ice sheet. Here we use transient climate-ice sheet simulations to simultaneously constrain estimates of regional temperature anomalies and Greenland's contribution to the MIS-11 sea-level highstand. We find that Greenland contributed 6.1 m (3.9-7.0 m, 95% credible interval) to sea level, ∼7 kyr after the peak in regional summer temperature anomalies of 2.8 °C (2.1-3.4 °C). The moderate warming produced a mean rate of mass loss in sea-level equivalent of only around 0.4 m per kyr, which means the long duration of MIS-11 interglacial conditions around Greenland was a necessary condition for the ice sheet to disappear almost completely.
古气候数据表明,在海洋同位素阶段 11(MIS-11)期间,格陵兰岛一定大部分时间没有冰。然而,与可能损失较少冰量的 MIS-5e 相比,这段时间格陵兰岛夏季太阳辐射异常幅度较小。因此,目前尚不清楚这些条件如何导致冰盖几乎完全消失。在这里,我们使用瞬态气候-冰盖模拟来同时约束区域温度异常的估计值以及格陵兰岛对 MIS-11 海平面高位期的贡献。我们发现,在区域夏季温度异常峰值后约 7000 年,格陵兰岛对海平面的贡献为 6.1 米(3.9-7.0 米,95%可信区间)。适度的变暖导致海平面当量的质量损失平均速率仅为每年约 0.4 米,这意味着格陵兰岛周围 MIS-11 间冰期条件的长时间持续是冰盖几乎完全消失的必要条件。