In 2023, we carried out the oceanographic cruise PASSAGE23, during which we deployed two mooring lines with several sediment traps and hydrographic sensors that will sample settling particles and the hydrological variability of the SW Iberian margin for 1 whole year. This is the first successful deployment of mooring lines in this highly hydrodynamic region, a benchmark area for paleoclimate investigations that has been the focus of countless (paleo)oceanographic cruises. Yet, no information on the yearly oceanography of the water column of the region has been produced so far. We will retrieve these moorings 1 year later, during cruise PASSAGE24, to produce novel knowledge on the provenance and transport pathways of proxy particles derived from sediment trap material and hydrographic sensors.
We have established the BiG lab, the new Biogeosciences Laboratory born under the framework of the PASSAGE project. BiG is an Organic Geochemistry lab, aimed at processing marine sediments, soils, and plants to extract, purify, and analyze the organic compounds they contain. Here we conduct routine analyses in Organic Geochemistry to let the organic molecules tell their climate stories.
We have advanced our understanding of the origin of the organic matter in marine sediments and the processes that determine its redistribution and final deposition in the Western Mediterranean Sea and the adjacent Atlantic Ocean (SW Iberian margin). Our work provides fundamental information to evaluate the potential origin of the pre-aged organic carbon found in the SW Iberian margin in the next steps of the project. This work is the subject of our latest publication “Publication of Sources and Fate of Sedimentary Organic Matter in the Western Mediterranean Sea” published in Global Biogeochemical Cycles.
In collaboration with our colleagues at ETH Zurich (Switzerland), we have developed and implemented a new methodology to sort, purify, and radiocarbon date coccoliths based on flow cytometry, a technique grounded in medicine and biology whose application to paleoclimate is still a budding field.
Our preliminary results on radiocarbon ages of coccolith-size classes provide unique insights into the differential impacts of specific hydrodynamic processes on coccoliths. Such a relationship informs about the complex hydrodynamic influence on the paleoclimate information extracted from these proxy particles, a relevant milestone of this project.
