ASEG NSW - talk by Berta Vilacís

Topic: ASEG NSW - talk by Berta Vilacís

Presenter: Berta Vilacís

Date and time: Sep 21, 2022 06:00 PM

Registration: https://us02web.zoom.us/webinar/register/WN_p_jGJ9-ESQaR2j_c9XroWQ

Overview:

Mantle convection is an essential driving force of plate tectonics. It affects the horizontal and vertical motion of the Earth’s surface. The horizontal motion of the lithosphere is observed in the spreading rates, while its vertical motion leaves an imprint the geological record. In particular, positive surface deflections driven by mantle convection create erosional/non-depositional environments, which induce gaps in the stratigraphic record (i.e., hiatus). Modern digital geological maps allow us to map no-/hiatus surfaces at continental scale systematically and use them as a proxy for mantle flow induced dynamic topography. We find that hiatus surfaces change in timescales of geological series. This is consistent with the presence of a weak upper mantle. Also, we find significant differences in the spatial scale of inter-regional hiatus, on the order of 2000-3000 km in diameter, which can be linked by fluid dynamic analysis to active upper mantle flow regions. Our results highlight the importance of geological datasets to further understand geodynamic processes in the deep Earth. Also, they indicate that studies of horizontal and vertical motion of the lithosphere to track past mantle flow would provide powerful constraints for adjoint based geodynamic inverse models of past mantle convection.

Bio:

Berta Vilacís is a PhD student in geodynamics at the Ludwig-Maximillians-Universität München (LMU Munich). She did her bachelor in Physics in the University of Barcelona focusing in applied seismology during her final year. At the same time she got a one-year fellowship in the Catalonia seismic network. After working in maintaining and processing data from the IEC seismic network in 2017, she moved to Munich where she got her MSc in Geophysics by TUM and LMU Munich. In 2019, she started her PhD in Hans-Peter Bunge’s group. Her research focuses in using geological information, such as geological maps, as a way to observe, map and track past mantle convection.