Araçá Bay: magnetic properties of sediments and their relationship with natural and anthropic processes

• Grant number: 15/18909-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2016
• End date: May 31, 2017
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Physical Oceanography
• Principal Investigator: Luigi Jovane
• Grantee: Gabriel Aleixo Maia
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/50317-5 - Biodiversity and functioning of a subtropical coastal ecosystem: a contribution to integrated management, AP.BTA.TEM

Abstract

This research project aims to analyze the magnetic properties of Araçá Bay's sediment samples. These are taken from cores previously collected for a thematic project funded by FAPESP, which seeks to generate a systemic understanding of the aforementioned region. Under this, we have selected profiles of magnetic susceptibility in three different frequencies of some of these cores, in which it is possible to observe changes in several depths. We propose the study of the relations between these changes in susceptibilities and other magnetic properties, as well as between anthropogenic activities and natural phenomena in the area. Using a Micromagnetometer, the intensity of the saturation field (Ms), remanence (Mr), coercivity (Hc) and remanent coercivity (Hcr) will be determined without causing deterioration of the samples. A susceptibility meter with a temperature control unity will be used in order to determine the Curie temperature (Tc) of the samples. Consequently, the results will be submitted to analysis, based on the precedents set on the literature of this study, aiming to characterize composition, granulometry and magnetic domain structure of the material responsible for the susceptibility changes. The obtained information will be interpreted taking into account human and historical factors of the area, in order to determine the existence of a relationship between the presence of the aforementioned material and the anthropic processes, as well as enable a further understanding of the region referred in this research. (AU)