Biogenic opal indicating less productive northwestern North Pacific during the glacial ages

Abstract

Biogenic opal and ice‐rafted detritus (IRD) data from sediments in the Okhotsk Sea and the neighboring North Pacific revealed the remarkable reduction in opal production and southward advancement of sea‐ice covered area during the last glacial maximum, resulting also southward shift of high biological productive area in the northwestern North Pacific. It implies that the substantial reduction in outflux of CO 2 to the atmosphere in northwestern North Pacific and the pronounced increase in CO 2 sequestering in temperate North Pacific. This could be an additional CO 2 reduction mechanism of atmospheric CO 2 in the last glacial period.