Sea level, nutrients, temperatures and ice sheets during gla

Sea level modulation of Nitrogen fixation during glacials

In this study we identified a link between the foraminifera-bound-δ15N (FB-δ15N) and variations in sea level over time. FB-δ15N was used to reconstruct changes in Nitrogen fixation across glacial/interglacial cycles. The data showed that Nitrogen fixation, a process that supplies the ocean with essential bioavailable nitrogen, is coupled to sedimentary denitrification on continental shelves. In turn, sedimentary denitrification depends on sea level with reduced denitrification rates during glacials when sea level is low and the shelf areas are exposed to air.

Coral reefs and warm sea surface temperatures

This study presents a 900,000-year TEX86-derived temperature record indicating that a ~2°C rise in summer sea surface temperatures (~26°C to ~28°C) around 700,000 years ago which likely triggered the onset of the Great Barrier Reef's growth by boosting carbonate production. We show that the reef's evolution and long-term stability have been closely tied to sustained warm sea surface temperatures.

Patagonian ice sheet changes

This study explores changes in the Patagonian ice sheet over the last 140'000 years. We show the connection between the sediment/meltwater release during cold phases and precipitation caused by enhanced westerly winds at the northwestern margin of the Patagonian ice sheet.

Migration of the Antarctic Circumpolar Current

This study provides biomarker-based evidence that the Antarctic Circumpolar Current's latitude fluctuations correlate with Earth's axial tilt and changes in atmospheric carbon dioxide levels during the last G/IG cycle.

Influences on mean ocean nitrate δ15N