Visiting researcher at Unicamp's Institute of Geosciences (IG), Marília Campos spent around 20 days on board the largest French research vessel, the Marion Dufresne, on an oceanographic expedition that departed from the capital of Suriname, Paramaribo, on June 12 and arrived to Recife (PE) on July 2, collecting, along the way, samples of marine sediments that record climate changes that the Earth has experienced. Campos is part of a group of researchers from Brazilian and foreign institutions who aim to advance the understanding of the interrelationships between the oceans, the planet's climate and biota.
During the oceanographic expedition, named Amaryllis and coordinated by Cristiano Chiessi, from the School of Arts, Sciences and Humanities of the University of São Paulo (USP), and by Aline Govin, from the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) , geological and geophysical data and sediment collection methods were used with the aim of reconstructing the climate history of that region. “When a proposal for a scientific expedition like this is created, in addition to the objectives of the expedition being defined very carefully, the group of researchers invited to participate is also carefully chosen. This is because the intention is for participants to establish and strengthen collaborative actions that will be based on the scientific material resulting from the expedition”, explains Campos. “Few researchers have the opportunity to participate in an expedition like this.”
Once on board, the researcher participated in several activities, such as sediment sampling, preparation of cores and carrying out analyzes on board the ship. With the end of the expedition, the next step is to distribute the collected material among the participants so that they can evaluate it according to their areas of study. “Once the scientific expedition is over, all the material is duly archived and divided for more detailed analysis. These analyzes will include geochemical (major and trace elements in total sediment, carbon and oxygen isotopes in carbonates, elements and isotopes in interstitial fluids) and sedimentological (particle size distribution, X-ray imaging) methods. With these data, the main objective of the Amaryllis expedition is to reconstruct the climatic history of the Amazon Basin and the Brazilian Northeast, as well as the surface and deep conditions of the adjacent ocean on different time scales (from decades to millions of years). In this way, it will be possible to reconstruct the temperature, salinity, type of vegetation and ocean circulation of the past”, explains Campos.
The Unicamp researcher is developing the Terra project (“The South Atlantic on a planet 2°C warmer”), which is based at IG and is funded by the São Paulo State Research Support Foundation (Fapesp). In this project, she seeks to understand the role of the South Atlantic in a past period, marked by intense climate change, with the aim of contributing to the identification of possible future scenarios. “The South Atlantic is particularly important for Earth's climate, as it is a huge reservoir of heat and plays a crucial role in transporting energy between the hemispheres. In this project, I intend to investigate the behavior of aspects of the surface and bottom of the South Atlantic during a warm period (interglacial) that occurred around 400 thousand years ago. This period is important, as it presented a global average temperature 2°C warmer than the temperature in the middle of the 2th century, known as 'pre-industrial'. Given that the scientifically and politically agreed limit (Paris Agreement) for global warming in the coming decades has been set well below XNUMX°C, relative to pre-industrial levels, the warm period targeted by the Terra project is an excellent case study. to investigate the behavior of the South Atlantic under such conditions”, he highlights.
In Campos' project, a combination of paleoclimatic indicators will be applied for the first time to at least six marine sedimentary cores from the Atlantic to reconstruct in detail their surface and deep conditions during that period. And one of the marine sedimentary cores collected on the Amaryllis expedition will be used in the researcher's project. “Most of the Terra project study sites have already been sampled in previous oceanographic expeditions. They are located along the Brazilian and African continental margin, as well as in the central region of the South Atlantic. On the Amaryllis expedition, we collected a core on a seamount located about 250 km off the coast of Maranhão, which covers the interglacial of interest to me. . I intend to use samples from this site to integrate the set of marine samples from the Terra project”, she explains.
According to the researcher, a collaborative network, in which researchers from Brazil and abroad participate, was structured, in her project, with the objective of supplying the necessary infrastructure to execute the proposed analytical techniques. “In addition, the researchers were invited with the aim of contributing to discussions about the results that will be produced, since many of them are also experts in the areas proposed in the project. It is worth mentioning that paleoceanography is an eminently multidisciplinary area, and the involvement of researchers from different specialties is essential to answer major scientific questions,” she explains. The Terra project counts, in Brazil, on the collaboration of researchers from Unicamp, USP, Unesp (Universidade Estadual Paulista), UFF (Universidade Federal Fluminense), UERJ (Universidade Estadual do Rio de Janeiro) and the National Laboratory of Synchrotron Light. Abroad, with researchers from Marum – Center for Marine Environmental Sciences at the University of Bremen (Germany), the Institute of Earth Sciences at the University of Heidelberg (Germany) and the Department of Earth Sciences at the University of Cambridge (United Kingdom). On the Amaryllis expedition, there were three researchers associated with the project coordinated by Campos: the aforementioned Chiessi, Ana Luiza Albuquerque, from the Department of Geology and Geophysics at UFF, and Vinícius Mendes, from the Instituto do Mar at the Federal University of São Paulo (Unifesp). Taking advantage of Campos' paleoceanography project, a new research group is being created at IG.
