Brief sea-level fall event and centennial to millennial sea-level variations during Marine Isotope Stage 19 in Osaka Bay
Brief sea-level fall event and centennial to millennial sea-level variations during Marine Isotope Stage 19 in Osaka Bay
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大阪湾海洋同位素阶段 19 期间短暂的海平面下降事件和百年至千年海平面变化
DOI：
10.1002/jqs.2907
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
H. Sato
中科院分区：
文献类型：
--
作者：
k. Maegakiuchi;M. Hyodo;I. Kitaba;K. Hirose;S. Katoh;H. Sato
根据大阪群海相层序的硅藻和粒度分析，研究了大阪群海相同位素19阶段的详细海平面变化。硅藻海平面代表与高水位MIS19.3和19.1、低水位MIS19.2相关的进动相关信号。天文调谐表明，海相层序具有约60 cm ka−1的均匀积累速率。在最早的MIS19发现了一次海平面快速下降事件，由几个独立的海平面硅藻和粒度代用来证明。这次事件开始于海平面的快速下降，随后逐渐恢复，约为783-782ka。深海硅藻在402.20 m处的最大丰度明显地显示了MIS19的最高海平面峰值，并得到了许多其他指标的支持。根据硅藻数据，MIS19.1的海平面变化具有百年至千年的波动特征。海平面下降事件发生在之前报道的同一地心冷却事件发生后不久。在许多深海岩心记录中观察到的类似海平面下降信号表明，这一事件是全球性的。
Detailed sea‐level variation was investigated for Marine Isotope Stage (MIS) 19, based on diatom and grain size analyses of a marine sequence in a core of the Osaka Group. Diatom sea‐level proxies represent precession‐related signals correlated with highstands MIS 19.3 and 19.1, and lowstand MIS 19.2. Astronomical tuning shows the marine sequence has a uniform accumulation rate of about 60 cm ka−1. A rapid sea‐level fall event was found in the earliest MIS 19, demonstrated by several independent sea‐level proxies of diatom and grain size. This event began with a rapid sea‐level drop, followed by a gradual recovery, at about 783–782 ka. A maximum abundance of pelagic diatom taxa at a core depth of 402.20 m evidently shows the highest sea‐level peak in MIS 19, supported by many other proxies. Based on the diatom data, sea‐level change across MIS 19.1 is characterized by centennial to millennial fluctuations. The sea‐level fall event began just after the onset of a cooling event previously reported from the same core. Observations of a comparable sea‐level fall signal in many deep‐sea core records suggest the event is global.