Age model built from planktic foraminifera radiocarbon in the eastern Pacific during the last deglaciation determined from core MAZ-1E-04 collected on cruise MAZ-I aboard the R/V El Puma in April 2015

The structure and drivers of oxygen minimum zone (OMZ) evolution in the Eastern Tropical North Pacific (ETNP) are investigated from ~20.7-10 ka using a multi-proxy approach from core MAZ-1E-04 (22°54.29’N, 106°54.59’W; 1463 m depth). Understanding how OMZ vertical structure changed during past glacial/interglacial cycles will help elucidate the drivers and patterns of OMZ expansion/contraction on longer timescales.

Here, the age model built from planktic foraminifera radiocarbon and calibrated with marine reservoir ages and the intcal20 calibration curve, based on samples from core MAZ-1E-04 collected on cruise MAZ-I aboard the R/V El Puma in April 2015, is used to investigate multiple geochemical proxies over the last deglaciation. Universidad Nacional Autónoma de México financed ship time and M. Alejandro Rodríguez Ramírez directed the oceanographic campaign to retrieve the core.