Strength of the lithosphere in Graham Land region (Antarctic Peninsula), derived from geological and geophysical data

Abstract

We explore the lithospheric strength in the Graham Land region of the Antarctic Peninsula (AP) through the integration of geological and geophysical data with numerical modeling. We used GNSS data and Glacial Isostatic Adjustment (GIA) models to derive velocity and strain fields, while rheological parameters and geothermal heat flow (GHF) provided constraints for calculating the lithospheric strength profile. The methodology incorporates the Yield Strength Envelope (YSE), a framework that characterizes lithospheric strength at varying depths by accounting for both brittle and viscous deformation. A key result is a refined model of vertical and horizontal velocity fields, revealing a dominant uplift with peak rates reaching approximately 12.7 mm yr${}^{-1}$. The strength model reveals a lithosphere with significant thermal variations, which are influenced by substrate composition and regional geodynamic processes. The analysis underscores that the lithosphere's mechanical behavior is strongly impacted by regional tectonic interactions and elevated geothermal heat flow. This work enhances understanding of Antarctic lithospheric dynamics, with implications for geological evolution and global climate change studies.