A GNSS-Derived Strain Rate Map of North America and Implications for Continental
Yuehua ZengSubmitted August 30, 2026, SCEC Contribution #15301, 2026 SCEC Annual Meeting Poster #061
This study presents a geodetic strain-rate model for the North American Continent derived from Global Navigation Satellite System (GNSS) velocity measurements. The model incorporates horizontal GNSS velocities compiled by Zeng (2022) for the western United States and Median Interannual Difference Adjusted for Skewness (MIDAS) (Blewitt et al., 2016) velocities from Nevada Geodetic Lab for the remainder of the continent. Strain rates are calculated using the methodology of Shen et al. (2015). The resulting model reveals distinct spatial patterns of crustal deformation across North America. High shear strain rates are observed along the entire western margin of the continent, particularly along the San Andreas Fault system. Elevated compressional strain rates are evident along major subduction zones, including the Alaska, the Cascadia, and the Cocos (at the southern margin of the continent) subduction zones. Regions of pronounced dilatational strain are identified along the Gulf of California rift zone, across the Yakutat Block, and within the Central Nevada Seismic Belt and Intermountain West Seismic Belt. Broad extensional strain is also evident across eastern Canada, consistent with post-glacial rebound processes. In contrast, low strain rates characterize much of the Basin and Range Province and most of the central and eastern United States. Overall, the spatial distribution of high strain rates correlates well with regions of elevated seismicity across the continent. This strain-rate model provides important constraints on continental deformation, supports improved seismic hazard assessments, and contributes to ongoing efforts to refine and update the North America stress map.
Key Words
GNSS geodesy, strain rate, crustal deformation, North America
Citation
Zeng, Y. (2026, 08). A GNSS-Derived Strain Rate Map of North America and Implications for Continental. Poster Presentation at 2026 SCEC Annual Meeting.
Related Projects & Working Groups
Tectonic Geodesy
