Premium
Intermediate water ventilation change in the subarctic northwest Pacific during the last deglaciation
Author(s) -
Sagawa Takuya,
Ikehara Ken
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035133
Subject(s) - deglaciation , salinity , geology , seawater , oceanography , subarctic climate , surface water , environmental science , holocene , environmental engineering
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 δ 18 O of seawater ( δ 18 O W ; 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 δ 18 O W 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.