Seminar

Intraplate volcanism is a key feature of how Earth works and how it loses internal heat. Our best representation of Earth, Plate Tectonics, does not satisfactorily explain it. Here, in my project, I would like to explore new ways to constrain geophysical characteristics of the most widely accepted geological process that explains intraplate volcanoes, a thermochemical rising mantle plume, using geodetic satellite methods. One of the main predictions of the mantle plume is an uplift of the lithosphere. We explore the feasibility of measuring such uplifts using geodetic satellite measurements to gain a more accurate understanding of the processes involved. We selected the African Tibesti intraplate region as a test case. We process satellite geodetic data from the Tibesti region to detect and characterize uplift induced by an underlying mantle plume. To achieve this, we use state-of-the-art COMET-Sentinel-1 products and InSAR techniques. Our preliminary results indicate some limitations of surface velocity precision achievable using COMET products. We discuss their overall precision and potential improvements in InSAR techniques to address these challenges during the PhD project. Despite these challenges, the processing using COMET products allowed us to identify three previously unrecognized local surface ground displacements anomalies. While these findings may not directly help unveil mantle plume uplift, we engage in a comprehensive discussion of the possible sources of these displacements as due to hydrological, hydrothermal or volcano-magmatic processes. We also emphasize the need for ongoing research and advanced techniques, such as addressing the main identified challenge (InSAR affecting atmospheric artifacts), to extend our ability to measure small-magnitude and wide-area mantle plume lithospheric deformation and enhance our understanding of the complex mechanisms driving intraplate volcanism.

Additional information: Mr. Mohammadhossein Mohammadnia, mhmnia@connect.hku.hk