Intermediate water ventilation change in the subarctic northwest Pacific during the last deglaciation
Intermediate water ventilation change in the subarctic northwest Pacific during the last deglaciation
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DOI：
10.1029/2008gl035133
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发表时间：
2008-12
影响因子：
5.2
通讯作者：
T. Sagawa;K. Ikehara
中科院分区：
文献类型：
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作者：
T. Sagawa;K. Ikehara
层状沉积物表明，在最后一次冰川消融期间，北太平洋中间水的溶解氧显著减少。然而，在冰川消融期间缺氧的原因仍然是一个有争议的问题。为了研究末次冰消期海水的中间水循环，我们研究了以有孔虫Mg/Ca为基础的中表层温度和海水的δ18O （δ18OW，盐度的代表）。结果表明，在Bølling‐allerld时期，中间水温和δ18OW随通气年龄的增加而升高，表明该时期通气较差。地表记录表明，盐度的降低先于中间通气的减慢。中水和地表水的耦合变化表明，高纬度地区由于地表更新导致通风不良，冷、新鲜的中水供应减少。
The laminated sediments suggest significant depletion in dissolved oxygen of intermediate water in the North Pacific during the last deglaciation. However, the cause of depleted oxygen during deglaciation is still a matter of debate. Here, we present foraminiferal Mg/Ca‐based intermediate and surface temperatures and δ18O of seawater (δ18OW; a proxy of salinity) in the Oyashio region in order to investigate intermediate water circulation through the last deglaciation. Results indicate that the intermediate water temperature and δ18OW increased in association with ventilation age at the Bølling‐Allerød period, suggesting that the poor ventilation at that time. The surface record shows that the decrease of salinity preceded the slowdown of intermediate ventilation. The coupled variation of intermediate and surface water suggests that the supply of cold, fresh intermediate water diminished because of poor ventilation at the high latitude due to surface freshening.