Title: The Origin and Evolution of Subduction in Early Earth: Insights from Geodynamic Models and Machine Learning-Based Detection
Abstract: Despite significant study when and how plate tectonics initiated
on Earth remains contentious. In this talk, I will explore how subduction zones formed and evolved during Earth’s early history, with a particular focus on their relationship to continental margins. This work uses numerical mantle convection models with grain-damage rheology to test whether early continents could trigger subduction, showing instead that subduction often initiated elsewhere and later migrated toward continents. I will then discuss two distinct styles of subduction (transient and persistent) and show that persistent subduction at continental margins emerged only after transient zones interacted with continents, on a timescale of roughly half a billion years. Finally, I will present a deep learning tool I developed to track subduction zones in numerical models, which improves accuracy compared to pre-existing velocity-based methods. Overall, this talk highlights the importance of rheology in subduction initiation, provides a geologically consistent timescale for the establishment of stable subduction, and introduces machine learning as a new way to study tectonic processes.
Biography: I am currently a postdoctoral fellow at Georgia Tech. I completed my PhD at Penn State in Spring 2025. My research broadly focuses on the dynamics of Earth’s interior, with an emphasis on how plate tectonics began and evolved on the early Earth. I use numerical modeling and machine learning to study the initiation and evolution of subduction zones, and how these processes shaped the earliest continents. Currently, I am developing models of early subduction to investigate how fluids migrated in Archean settings and how this fluid transport may have influenced the formation and stabilization of Archean continental crust.
To join virtually: Zoom
Contact: hchoi342@gatech.edu
Website: https://heec12.github.io/
Recording: Zoom Recording (will be available within a week after the seminar)