Statewide Community Thermal Model of California and Nevada: Model comparisons, implications, and a new explorer platform

Terry Lee, Andrew V. Zuza, Daniel T. Trugman, Dominik R. Vlaha, & Wenrong Cao

Submitted September 7, 2025, SCEC Contribution #14291, 2025 SCEC Annual Meeting Poster #TBD

The temperature variation in the continental crust influences various solid Earth processes, including seismicity, rheology, and stress state. Therefore, deciphering the crustal thermal structure can provide insights into seismic hazards, crustal deformation, and beyond. A major initiative is to broaden the Community Thermal Model (CTM) to a California statewide scale and provide platforms to access and visualize various models. Here, we present a new statewide CTM of California and Nevada constrained by geophysical temperature proxies across the crustal columns, including surface heat flow, seismogenic thickness inferred from earthquake records, Moho temperature, and crustal thickness. Our model adapts a Monte Carlo approach, generating unknown thermal parameters (e.g., radiogenic heat production, thermal conductivity) to determine the 1D steady-state conductive thermal profiles that best match the independent temperature proxies. Our statewide CTM also contains an open-sourced Python software package, enabling users to test our thermal model with modified parameters and input temperature proxies. Ongoing efforts involve developing a new CTM explorer tool that allows the users to download and visualize 3D temperature data across all CTMs. Based on our new statewide CTM, the hot thermal structures (>600 °C at 20 km) in the Salton Trough, Clear Lake, Coso volcanic field, and Central Nevada Seismic Belt are consistent with the distribution of geothermal power plants and <10 Ma volcanism. The lack of temperature fits in tectonic domains such as southern Sierra Nevada reflects that non-steady state thermal regimes (e.g., mantle heating, hydrothermal circulation) may be affecting these regions. Cross-evaluation of our statewide CTM against existing southern California CTMs reveals a strong consistency, although our model is generally warmer by ~45°C. We also assessed temperature uncertainty across all CTMs by incorporating independent temperature proxies, including Curie depth and temperature-pressure estimates from Quaternary xenoliths. Lastly, we demonstrated the versatility of our new modeling framework by implementing the thermal model to East Asia and evaluating crustal rheology of California and Nevada based on our statewide CTM.

Key Words
Statewide Thermal Model, Rheology, Seismogenic Thickness

Citation
Lee, T., Zuza, A. V., Trugman, D. T., Vlaha, D. R., & Cao, W. (2025, 09). Statewide Community Thermal Model of California and Nevada: Model comparisons, implications, and a new explorer platform. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Community Earth Models (CEM)