The July 2025 magnitude 8.8 Kamchatka earthquake unleashed a rupture spanning roughly 500 kilometers (311 miles) from its epicenter, according to a new analysis. Scientists combined two methods to reconstruct the evolution of the megathrust event.
That rupture zone overlaps with the site of the 1952 Kamchatka earthquake, one of the largest ever recorded. The finding suggests the same section of the subduction zone may be capable of generating repeated massive quakes.
Researchers used both seismic waveform data and geodetic measurements to map the rupture's progression. The 500-kilometer length makes it one of the longest rupture zones observed in modern seismology.
The overlap with the 1952 event raises questions about seismic hazard in the region. It suggests the Kamchatka subduction zone can produce successive giant earthquakes along the same fault segment, challenging assumptions about stress release cycles.
The study's methods could improve real-time monitoring of megathrust earthquakes elsewhere, though researchers caution that each subduction zone behaves differently.