Abyssal seafloor as a key driver of ocean trace-metal biogeochemical cycles.

Trace elements and isotopes (TEIs) are important to marine life and are essential tools for studying ocean processes. Two different frameworks have arisen regarding marine TEI cycling: reversible scavenging favours water-column control on TEI distributions, and seafloor boundary exchange emphasizes sedimentary imprints on water-column biogeochemistry. These two views lead to disparate interpretations of TEI behaviours.

Prevalent North Atlantic Deep Water during the Last Glacial Maximum and Heinrich Stadial 1.

Deep ocean circulation modulated glacial-interglacial climates through feedbacks to the carbon cycle and energy distribution. Past work has suggested that contraction of well-ventilated North Atlantic Deep Water during glacial times facilitated carbon storage in the deep ocean and drawdown of atmospheric CO levels. However, the spatial extent and properties of different water masses remain uncertain, in part due to conflicting palaeoceanographic proxy reconstructions.