Building of the first optically stimulated luminescence scanner for marine sediment cores

• Grant number: 24/00942-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2024
• End date: February 28, 2026
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Vinícius Ribau Mendes
• Grantee: Giorgio Battistella Santos
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated research grant: 22/02957-0 - Effects of the South Atlantic warming over South American precipitation, AP.PNGP.PI
• Associated scholarship(s): 25/08809-0 - Spatially Resolved Luminescence in marine sediment cores, speleothems, and corals, BE.EP.MS

Abstract

The sedimentary records from marine sediments are among the most widely used archives for reconstructing late Quaternary climate and oceanographic changes. A large number of proxies based on the biological, chemical, physical, and isotopic properties of sediments are available, enabling the reconstruction of essential climate and oceanic parameters. For example, temperature, salinity, primary productivity, upper water column stratification, and continental precipitation are routinely reconstructed.Among these parameters, the reconstruction of changes in continental precipitation at a watershed scale (river discharge) is of crucial importance for understanding the response of rivers and forests to climate changes. Reconstructions of changes in continental precipitation, archived in marine sediment cores, can be conducted, for instance, through records of leaf wax isotopes (´D) and elemental ratios such as Fe/Ca. However, the interpretation of leaf wax isotopes (´D) depends on the concentration of n-alkanes in marine sediments, and elemental ratios can be influenced by other factors, such as weathering degree in sediment source areas, sediment grain size, sea-level changes, primary productivity, and post-depositional processes.Therefore, to obtain a signal that is relatively faster to acquire, reliable, and proportional to precipitation changes, a precipitation indicator based on quartz luminescence has been developed. Luminescence is a relatively easily measurable physical property, and quartz is very stable against weathering and abundant in sediments, providing a significant advantage to the method. In this project, we propose to design and construct an optically stimulated luminescence scanner for the study of marine sediment cores. The promising results obtained with this new precipitation proxy and the relative ease of obtaining luminescence signals support the idea of the necessity and feasibility of constructing this equipment. Obtaining results more quickly and at higher resolution could bring significant benefits to the field of paleoclimatology.