Preliminary slip distribution of the July 29, 2025 M 8.8 Kamchatka, Russia earthquake

The Mw 8.8 Kamchatka earthquake in Russia’s Kamchatka Peninsula is one of the top ten largest earthquakes worldwide since 1900. This event occurred in a tectonically active Kurile–Kamchatka subduction zone where several large earthquakes (M>8) have occurred over the past 100 years. Here, we combine the teleseismic vertical-component P-wave back-projection method and finite fault inversion with teleseismic P and SH waveforms to investigate the kinematic features of this earthquake. The results indicate that the ruptured area spans approximately 600 km in length and 175 km in width, with a total source duration of about 220 seconds. Moreover, the coseismic slip occurred mainly within the subducting interface away from the trench, reaching a maximum slip of about 8 m. Notably, the rupture propagated approximately 500 km southwestward from the hypocenter, consistent with the aftershock distribution. These results imply that the rupture zone of this earthquake might spatially overlap with that of the 1952 Mw 8.8-9.0 Kamchatka earthquake. Furthermore, the smaller than anticipated tsunami generated by this megathrust event could be attributed to its limited shallow slip near the trench. This study provides preliminary kinematic insights into this event and lays a certain foundation for subsequent in-depth studies.