The slip distributions of the 1952 and 2025 Kamchatka earthquakes from tsunami waveforms recorded around the Pacific Ocean

Yushiro Fujii, Kenji Satake

The July 2025 Kamchatka earthquake (Mw 8.8) generated Pacific-wide tsunamis. Inversion of 40 DART bottom pressure records around the Pacific Ocean revealed a large (~ 9 m) slip at 200 – 400 km southwest of the epicenter, closely matching the USGS finite fault model based on teleseismic data. In this region, a similarly large megathrust earthquake (M ~ 9) occurred in 1952. The tsunami waveforms recorded at tide gauge stations around the Pacific Ocean were very similar to those of the 2025 earthquake. We also made an inversion of the 1952 tide gauge data to estimate the slip distribution and clock correction at each station, considering the elasticity of the Earth and sea water and the station corrections. The 1952 slip distribution is similar to that of 2025, except for the depth of the largest slip and the northern slip where foreshock and aftershocks occurred in 2025.