Marine isotope stage M2 (~3.3 Ma) in the southern hemisphere: constraining the climatic drivers of a short-term glaciation event during the mid-Pliocene warm Period.

在3.5-3.0 Ma之间，全球气候以异常的气候变化为特征。约3.3 Ma左右，一次短暂但强烈的冰川作用中断了上新世相对温暖的气候。直到今天，还存在着不同的假设来解释为什么这次冰川事件如此强烈，以及为什么全球气候系统相对较快地恢复到上新世的温暖条件。这些拟议的机制之一是减少热流，从低层到高纬度，从太平洋到印度洋，通过印度尼西亚海道。由于澳大利亚大陆向北移动和海洋大陆(新几内亚和印度尼西亚)的抬升，通过这条海道的水流在4至3 Ma之间受到限制。这项提议旨在通过在U1463站位3.5-3.0 Ma期间产生2-3KYR分辨率的浮游有孔虫氧同位素记录来评估这一领先假说。U1463站点是2015年9月国际海洋发现计划探险356印度尼西亚Throughflow期间在澳大利亚西北部大陆架钻探的，恰好位于印度尼西亚海道的出口处。与赤道西太平洋806站现有的浮游有孔虫氧同位素记录相比，U1463站新产生的记录将为评估印度尼西亚海道在调节太平洋和印度洋之间热流方面的作用提供一个独特的机会。

Between 3.5 and 3.0 Ma, global climate was characterized by exceptional climate variability. A brief (<100 kyr) but intense glaciation interrupted the relatively warm climate of the Pliocene around 3.3 Ma. Until today, different hypotheses exist to explain why this glaciation event was so intense, and why the global climate system returned to warm Pliocene conditions relatively quickly. One of these proposed mechanisms is a reduced heat flow, from the low towards the high latitudes and from the Pacific to the Indian Ocean, through the Indonesian seaway. The flow through this seaway became restricted between 4 and 3 Ma because of the northward movement of the Australian continent and the uplift of the maritime continent (New Guinea and Indonesia). This proposal aims to evaluate this leading hypothesis by generating a 2-3 kyr resolution planktonic foraminiferal oxygen isotope record for the interval 3.5 - 3.0 Ma for Site U1463. Site U1463 was drilled during International Ocean Discovery Program Expedition 356 Indonesian Throughflow in September 2015 on the Northwestern Australian Shelf, and is located exactly at the outflow of the Indonesian seaway. When compared to the existing planktonic foraminiferal oxygen isotope record from Site 806 in the western equatorial Pacific, the newly generated record for Site U1463 will provide a unique opportunity to evaluate the role of the Indonesian seaway in regulating the heat flow between the Pacific and Indian Ocean.