The Rupture Surface Model of the July 29, 2025 Mw 8.8 Kamchatka Earthquake Based on Satellite Geodesy and Interferometry Data

For the July 29, 2025 Mw 8.8 Kamchatka earthquake, a seismic rupture surface model is constructed and a displacement field on it is determined, using coseismic displacements at the stations of the Kamchatka GNSS network and a displacement map based on satellite radar interferometry data. The model consists of four rectangular segments, dipping at 8° in the upper part and 21° deeper than 20 km. The main displacements on the rupture surface up to 11.5 m are obtained in the area of the southern part of the Kamchatka Peninsula and near Shumshu and Paramushir islands. In the area of Avacha Bay, they are twice as small. Such a distribution of displacements on the seismic rupture is completely consistent with the available GNSS and InSAR data and with the height of tsunami waves. The average displacement on the rupture surface is 6.5 m, which corresponds to the displacement deficit accumulated since the recent major earthquake in this area in 1952. The comparison of the displacement fields on the rupture surface of the 2025 earthquake with the 1952 rupture surface model, constructed using the data of tsunamigenic deposits, shows that the displacements complement each other: where large displacements occurred in 1952, the displacements were smaller in 2025 and vice versa.