Influence of northwest Pacific productivity on North Pacific Intermediate Water oxygen concentrations during the Bølling-Ållerød interval (14.7-12.9 ka)

Elevated productivity in the northwest Pacific is suggested as a new possible control driving past intervals of low-O₂ intermediate water along the western continental margin of North America. According to this mechanism, O₂ consumption would occur near the site of formation of North Pacific Intermediate Water (NPIW), due to increased respiration of organic carbon in response to a high-productivity event. Evidence is provided for such a productivity increase during the Bølling-Ållerød interval (14.7–12.9 ka), a time when laminated sediments were deposited along the northern California margin. By this mechanism, low-O₂ events in intermediate waters off the western North American margin could occur without significant changes in the rate of NPIW ventilation.