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Bølling-Allerød productivity in the subarctic Pacific driven by seasonal upwelling

Kimberly A. deLong·Terrence Blackburn·Beth E. Caissie·Jason A. Addison·Zuzanna Stroynowski·Maria R. Sipala·Franco Marcantonio·Ana Christina Ravelo
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Abstract

The Bølling-Allerød deglacial event is marked by high diatom productivity and opal deposition throughout the subarctic Pacific. This opal could either constitute a strengthened biological pump and thus carbon sequestration, or a weakened biological pump and release of marine-sequestered CO 2 to the atmosphere. We quantify silicic acid supply at IODP Site U1340 in the Bering Sea using biogenic opal and δ 30 Si of Coscinodiscus , a diatom genus. These records, along with diatom environmental indicators, suggest the Bølling-Allerød had high silicic acid availability related to a shift from stratification to seasonal upwelling dynamics. We thus propose the primary cause of the high productivity event was increased macronutrient supply from vertical exchange that injected old, nutrient-rich, CO 2 -rich waters into the surface. Enhanced CO 2 release from the subarctic Pacific may help explain critical intervals of CO 2 rise that occur at the onsets of the Bølling-Allerød and PreBoreal.

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Geophysical Research LettersArticle

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Kimberly A. deLong, Terrence Blackburn, Beth E. Caissie, Jason A. Addison, Zuzanna Stroynowski, Maria R. Sipala, Franco Marcantonio, Ana Christina Ravelo. 2025-04-26. Bølling-Allerød productivity in the subarctic Pacific driven by seasonal upwelling. https://doi.org/10.1029/2024gl109614

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