Dynamic Model of the Source of the Kamchatka Earthquake of July 29 (30), 2025, Based on GNSS Data

A source model of the July 29 (30), 2025 Kamchatka earthquake (MW ≈ 8.7–8.8) is presented based on GNSS data processed using different primary processing schemes: high-rate observations (1 Hz) and daily averaged solutions. It is shown that both processing types reliably reproduce the principal spatial and energy characteristics of the seismic rupture; however, proper accounting for postseismic displacements is required when interpreting daily averaged data. The use of high-rate data made it possible to reconstruct a spatiotemporal rupture propagation model. The rupture propagated unilaterally for ~180 s at an average velocity of ~1.67 km/s, significantly slower than the shear‑wave velocity in the upper crust. Such a slow rupture propagation regime may explain the relatively moderate macroseismic effects and comparatively limited amplitude of the generated tsunami.