An atmospheric chronology for the glacial-deglacial Eastern Equatorial Pacific.
An atmospheric chronology for the glacial-deglacial Eastern Equatorial Pacific.
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DOI：
10.1038/s41467-018-05574-x
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发表时间：
2018-08-06
影响因子：
16.6
通讯作者：
Keigwin LD
中科院分区：
文献类型：
--
作者：
Zhao N;Keigwin LD
古气候重建的准确性取决于它们的年代学。特别是，不同的海洋沉积物岩心年代学假设可能导致海洋通风年龄和大气-海洋碳交换历史的不同重建。在这里，我们建立了第一个高分辨率的年表，它没有海洋沉积物记录中常见的测年不确定性，基于在东赤道太平洋（EEP）的两个岩心中通过计算机断层扫描发现的放射性碳测年树枝。利用这一准确的年代学，我们发现在末次盛冰期和消冰期，东洋极温层和中间水域的通气年龄与今天相似，这与以往的研究结果相矛盾。我们的研究结果表明，EEP中冰川呼吸碳库的年龄并不比现在明显，赤道太平洋碳源的消冰强化可能是由低纬过程驱动的，而不是由高纬度海洋上涌碳的地下供应增加驱动的。海洋沉积物记录中的年代假设可能导致古环境重建的不确定性。在这里，作者使用计算机断层扫描来识别原位木质碎屑，构建了一个可靠的14C年表，并重新评估了LGM期间东赤道太平洋的通风年龄。
Paleoclimate reconstructions are only as good as their chronology. In particular, different chronological assumptions for marine sediment cores can lead to different reconstructions of ocean ventilation age and atmosphere−ocean carbon exchange history. Here we build the first high-resolution chronology that is free of the dating uncertainties common in marine sediment records, based on radiocarbon dating twigs found with computed tomography scans in two cores from the Eastern Equatorial Pacific (EEP). With this accurate chronology, we show that the ventilation ages of the EEP thermocline and intermediate waters were similar to today during the Last Glacial Maximum and deglaciation, in contradiction with previous studies. Our results suggest that the glacial respired carbon pool in the EEP was not significantly older than today, and that the deglacial strengthening of the equatorial Pacific carbon source was probably driven by low-latitude processes rather than an increased subsurface supply of upwelled carbon from high-latitude oceans. Chronological assumptions in marine sediment records can result in uncertainties in paleoenvironmental reconstructions. Here, using computed tomography to identify in situ woody debris, the authors construct a robust 14C chronology and reassess ventilation ages in the Eastern Equatorial Pacific during the LGM.
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影响因子：
5.2
作者：
Key, RM;Kozyr, A;Peng, TH
通讯作者：
Peng, TH
影响因子：
64.8
作者：
FAIRBANKS, RG;SVERDLOVE, M;BE, AWH
通讯作者：
BE, AWH
影响因子：
16.6
作者：
de la Fuente M;Skinner L;Calvo E;Pelejero C;Cacho I
通讯作者：
Cacho I
影响因子：
5.3
作者：
Davies-Walczak, Maureen;Mix, A. C.;Xuan, C.
通讯作者：
Xuan, C.
影响因子：
--
作者：
de la Fuente, Maria;Calvo, Eva;Cacho, Isabel
通讯作者：
Cacho, Isabel