Planktic foraminifera assemblages 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 planktic foraminiferal assemblages alongside multiple other proxies 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.

Planktic foraminifera assemblage counts from core MAZ-1E-04, collected on cruise MAZ-I aboard the R/V El Puma in April 2015, are used here to explore any composition shifts driven by environmental changes. Universidad Nacional Autónoma de México financed ship time and M. Alejandro Rodríguez Ramírez directed the oceanographic campaign to retrieve the core.