The Peruvian oxygen minimum zone was similar in extent but weaker during the Last Glacial Maximum than Late Holocene

Abstract Quantifying past oxygen concentrations in oceans is crucial to improving understanding of current global ocean deoxygenation. Here, we use a record pore density the epibenthic foraminifer Planulina limbata from Peruvian Oxygen Minimum Zone reconstruct bottom waters Last Glacial Maximum Late Holocene at 17.5°S about 500 meters below sea surface. We found that levels were 40% lower during than (about 6.7 versus 11.1 µmol/kg, respectively). A comparison with other reconstructions region reveals shallow was similar water depth and extent but weaker Holocene. Increased glacial are probably related temperatures (higher solubility), decreased nutrient increased supply by source waters, decrease coastal upwelling.