Source Parameters of Strong Kamchatka Earthquakes in 2025 (MW > 7.0) from Surface Wave Data

We consider four strong earthquakes with MW > 7.0 that occurred in 2025 near the Kamchatka Peninsula: the foreshock on July 20, mainshock on July 29, and two aftershocks on September 13 and 18. Their source parameters are estimated from teleseismic surface wave records in instant point and finite-fault (elliptical dislocation with a finite duration) source approximations. In addition, rupture planes are identified based on seismological data. The obtained rupture lengths of the study seismic events are discussed in detail as they are characterized by good resolution. They are compared to USGS finite-fault models, distributions of aftershocks, and some existing scaling relations between subsurface rupture length and magnitude. The July 29, 2025 mainshock is also compared to the November 4, 1952 earthquake with MW = 8.8–9.0. Two scaling relations, providing the best fitting for earthquakes with MW ≥ 8.0, are selected based on the obtained results and USGS data.