• Spectral analysis of magnetic data defines Curie depth beneath caldera. • Curie-depth-guided 3D FE conductive thermal modeling optimization. • Earthquakes clustering matching hydrothermal features and fault traces location. • Brittle-Ductile Transition under high strain rates aligns with seismicity cut-off. The Yellowstone Volcanic Complex (YVC) is a high-temperature silicic magmatic system characterized by elevated heat flow, persistent seismicity, and widespread hydrothermal circulation. Assessing geothermal potential and volcanic hazard requires robust understanding of the crustal thermal structure and rheological behavior, which currently remain poorly constrained. Here, we develop a suite of 3D steady-state conductive thermal models of the YVC lithosphere, constrained by simplified crustal stratigraphy, seismic tomographically imaged magmatic bodies, and a Curie isotherm derived from spectral analysis of high-resolution aeromagnetic data. Model parameters were systematically optimized to minimize the misfit between modeled and observed Curie depth. Among several explored thermal simulations, the optimal one requires, in addition to the contribution of magmatic sources, distributed heat sources within the upper crust. In parallel, earthquakes from 1994 to 2024, analyzed using a density-based clustering algorithm reveal a shallow seismogenic layer (< 8 km) that coincides with steep thermal gradients and structurally controlled features such as active faults and hydrothermal systems. Subsequently, the optimized 3D thermal distribution was used to investigate several rheological scenarios. The retrieved sharp BD transition (∼7–8 km in depth) driven by elevated geothermal flux, partial melt, and by high strain rates (∼10 −8 s −1 ) reflects the seismicity cut-off. The performed thermo-rheological structure represents a long-term, time-averaged conductive framework describing the first-order crustal-scale mechanical architecture of the YVC. The integration of geophysical, thermal, and seismic data provides new constraints on the stable thermo-rheological structure of the YVC and underscores the value of Curie-depth-guided thermal modeling for imaging active magmatic systems.
Perrini et al. (Wed,) studied this question.