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>Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation
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Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation
During the last glacial termination, the upper North Pacific Ocean underwent dramatic and rapid changes in oxygenation that lead to the transient intensification of oxygen minimum zones (OMZs), recorded by the widespread occurrence of laminated sediments on circum-Pacific continental margins. We present a new laminated sediment record from the mid-depth (1100 m) northern Bering Sea margin that provides insight into these deglacial OMZ maxima with exceptional, decadal-scale detail. Combined ultrahigh-resolution micro-X-ray-fluorescence (micro-XRF) data and sediment facies analysis of laminae reveal an alternation between predominantly terrigenous and diatom-dominated opal sedimentation. The diatomaceous laminae are interpreted to represent spring/summer productivity events related to the retreating sea ice margin. We identified five laminated sections in the deglacial part of our site. Lamina counts were carried out on these sections and correlated with the B?lling–Aller?d and Preboreal phases in the North Greenland Ice Core (NGRIP) oxygen isotope record, indicating an annual deposition of individual lamina couplets (varves). The observed rapid decadal intensifications of anoxia, in particular within the B?lling–Aller?d, are tightly coupled to short-term warm events through increases in regional export production. This dependence of laminae formation on warmer temperatures is underlined by a correlation with published Bering Sea sea surface temperature records and δ18O data of planktic foraminifera from the Gulf of Alaska. The rapidity of the observed changes strongly implies a close atmospheric teleconnection between North Pacific and North Atlantic regions. We suggest that concomitant increases in export production and subsequent remineralization of organic matter in the Bering Sea, in combination with oxygen-poor waters entering the Being Sea, drove down oxygen concentrations to values below 0.1 mL L?1 and caused laminae preservation. Calculated benthic–planktic ventilation ages show no significant variations throughout the last deglaciation, indicating that changes in formation rates or differing sources of North Pacific mid-depth waters are not prime candidates for strengthening the OMZ at our site. The age models established by our correlation procedure allow for the determination of calendar age control points for the B?lling–Aller?d and the Preboreal that are independent of the initial radiocarbon-based chronology. Resulting surface reservoir ages range within 730–990 yr during the B?lling–Aller?d, 800–1100 yr in the Younger Dryas, and 765–775 yr for the Preboreal.
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机译：在最后的冰川终止期间，上北太平洋的氧气急剧和快速变化，导致氧气最小区域（OMZS）的瞬态强化，记录在循环陆地边缘的层压沉积物的普遍发生。我们从中间深度（1100米）北部波动海底裕度中提出了一种新的层压沉积物记录，提供了与卓越的十二型尺度细节的洞察中的洞察力。结合超高分辨率微X射线荧光（Micro-XRF）数据和沉积物相分析薄膜揭示了主要是令人害怕和硅藻占蛋白石沉降的交替。硅藻土层被解释为代表与撤退海冰缘相关的春季/夏季生产力事件。我们在我们网站的冥想部分中确定了五个层压部分。在这些部分上进行了层数，并与北格陵兰冰核（NGRIP）氧同位素记录中的B？Ling-aller？D和Preboreal阶段相关，表明各个椎板对联的年沉积（变化）。观察到的缺氧的快速截止数，特别是在B？Lling-aller？D内，通过区域出口生产的增加紧密地加上短期温暖事件。通过与阿拉斯加海湾的综合性海海表面积温度记录和综合性传染率的Δ18O数据的相关性强调了Laminae形成对暖温度的这种依赖性。观察到的变化的速度强烈意味着北太平洋与北大西洋地区之间的紧密大气扎切。我们建议伴随出口产量和随后的膨胀海中有机物质的再融化，与进入海洋进入的氧气贫瘠的水，将氧气浓度驱动至低于0.1ml L 2的值并导致薄层保存。计算出的底栖综合血管通风年龄在最后一个嗜好中没有显着变化，表明形成率或北太平洋中间深度水域不同的变化不是加强我们网站上的欧姆的候选人。由我们的相关程序建立的年龄模型允许确定B？Lling-aller？D的日历年龄控制点和与基于初始的无线电金的年表无关的偏见。在B？Ling-aller？D，较年轻的Drose中的800-1100yr，765-775 YR为妊娠，所产生的表面储层在730-990 YR之内。
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