Influence of large fluvial incisions on the lithospheric stress field: a numerical geodynamic perspective

• Grant number: 24/08784-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2024
• End date: April 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Victor Sacek
• Grantee: Felipe Baiadori da Silva
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Erosive and depositional processes acting along large fluvial incisions are responsible formoving important volumes of material on Earth's surface. In this way, the distribution of mechanical loads acting on the lithosphere varies through geologic time. The isostatic response to surface mass redistribution is inherently linked to the subsurface stress field, the latter being determined, essentially, by lithospheric rheology and the geometry and magnitude of loads applied through time. The consequences of stresses induced by incision of large rivers are diverse: on the one hand, the evolution of the continental landscape is directly influenced by these stresses, which rule the pattern of uplift and subsidence on the surface; on the other hand, stresses within the crust with sufficient magnitude to reactivate preexisting brittle structures may provide a partial explanation to the occurrence of seismic activity in the continental interior. This project aims at studying in detail the sensitivity of the stressfield induced by large fluvial incisions to parameters related to lithospheric rheology anderosive history, using a numerical model coupling surface and thermomechanical processes. Particular attention will be given to the evolution of the landscape resulting from the simulations, and to the magnitude of stresses induced in the presence of brittle structures in the crust, in order to contribute to explaining the intraplate seismicity observed in certain continental regions.