NOAA/WDS Paleoclimatology - Barbados - Extended Last Glacial Maximum Sea Level Record

Fundamental characteristics of the climate system during the most recent precessional cycle of the Earth's orbit around the Sun consist of the final expansion of land ice to its maximum extent, the subsequent episode of deglaciation, and the variations of global sea level that accompanied these events. In order to address the important issue of the variation of continental ice volume and related changes in global sea level through the late glacial period, we employ an extended set of observations of the pre-glacial and postglacial history of sea-level rise at the island of Barbados, together with a refined model of continental deglaciation and an accurate methodology for the prediction of postglacial sea-level change. Although our results provide unambiguous evidence that the post LGM rise of eustatic sea-level was very close to the widely supported estimate of 120 m, the data also provide evidence that LGM must have occurred 26,000 years ago, approximately 5000 yr earlier than the usually assumed age.

地球绕日公转的最近一次岁差周期内，气候系统的基本特征包括陆冰扩张至最大规模的最终阶段、随后的冰消期，以及伴随上述事件的全球海平面变化。为探究晚冰期以来大陆冰量变化及相关全球海平面变化这一核心科学问题，本研究采用了一套涵盖巴巴多斯岛冰期前后海平面上升演化历史的扩展观测数据集，并结合改进的大陆冰消作用模型与精准的冰后海平面变化预测方法。尽管本研究结果明确证实，末次冰盛期（Last Glacial Maximum，LGM）后的全球海平面升降幅度非常接近学界广泛认可的120米估算值，但该数据集同时表明，末次冰盛期发生于2.6万年前，比通常认定的年代早约5000年。