Crustal Structure and Magmatic System of Mount Erebus in Antarctica constrained by Receiver Functions and Seismic Velocity Analysis

Mount Erebus, the world’s southernmost active volcano in Antarctica, offers a unique opportunity to investigate crustal controls on persistent magmatism within a caldera environment. New seismic constraints reveal a thin (~ 20 km) and compositionally heterogeneous crust beneath Erebus, consistent with long-lived lithospheric extension associated with the Terror Rift and the Ross Sea. Bulk crustal Vp/Vs ratios vary from ~ 1.61–1.94, indicating pronounced crustal heterogeneity. Elevated Vp/Vs at mid-crustal depths, combined with localized reductions in shear-wave velocity, define thermally modified zones that are consistent with intrusive complexes or transient magma storage above the Moho. While these features align with the mafic-intermediate volcanic products of Mount Erebus, interpretations invoking partial melt or compositional variations remain inherently non-unique. Additionally, a CO2 rich magma reservoir and localised silica-enriched domains could further modify crustal properties and locally reduce Vp/Vs ratio. Although deeper mantle contributions to Erebus magmatism remain unresolved, the results emphasize the importance of crustal-scale processes in sustaining long-lived volcanism beneath Mount Erebus. This study highlights the importance of integrating geophysical data to understand complex melt distribution beneath caldera systems and offers new insights into magma plumbing in extensional intraplate settings.