State Key Laboratory of Marine Geology, Tongji University, Shanghai, China.
Department of Geosciences, University of Massachusetts, Amherst, MA, USA.
Sci Adv. 2023 Feb 24;9(8):eadd1467. doi: 10.1126/sciadv.add1467.
Antarctic bottom water (AABW) production is a key factor governing global ocean circulation, and the present disintegration of the Antarctic Ice Sheet slows it. However, its long-term variability has not been well documented. On the basis of high-resolution chemical scanning of a well-dated marine ferromanganese nodule from the eastern Pacific, we derive a record of abyssal ventilation spanning the past 4.7 million years and evaluate its linkage to AABW formation over this period. We find that abyssal ventilation was relatively weak in the early Pliocene and persistently intensified from 3.4 million years ago onward. Seven episodes of markedly reduced ocean ventilation indicative of AABW formation collapse are identified since the late Pliocene, which were accompanied by key stages of Northern Hemisphere glaciation. We suggest that the interpolar climate synchronization within these inferred seven collapse events may have intensified global glaciation by inducing poleward moisture transport in the Northern Hemisphere.
南极底层水（AABW）的产生是控制全球海洋环流的关键因素，而南极冰架的目前解体则减缓了这一过程。然而，其长期变化尚未得到很好的记录。基于对东太平洋一颗具有良好年代学的深海铁锰结核的高分辨率化学扫描，我们得出了过去 470 万年深海通风的记录，并评估了其与这一时期南极底层水形成的关系。我们发现，上新世早期的深海通风较弱，从 340 万年前开始持续增强。自上新世晚期以来，已经确定了七个明显降低的海洋通风事件，表明南极底层水形成崩溃，这些事件伴随着北半球冰川作用的关键阶段。我们认为，在这七个推断的崩溃事件中，极地间气候的同步可能通过在北半球向极地输送水分，从而加剧了全球冰川作用。
