The East African Rift System (EARS), one of the world’s most prominent continental rift and subsidence zones, is frequently affected by ground fissure hazards. These fissures pose serious challenges to infrastructure and community safety in the region. Consequently, understanding ground fissures within the rift is critical for elucidating the evolution of active rift-related hazards and for informing engineering and planning efforts in rift zones.
        In this study, we conducted extensive field surveys, trench investigations, geophysical measurements, and laboratory analyses of volcanic rocks and gas samples in the Kenyan segment of the EARS. Integrating multi-scale numerical simulations with large-scale physical modeling, we systematically characterize fissure distribution, identify deep-seated origins, and elucidate formation and evolution mechanisms.
        Our results reveal 83 ground fissures in the study area, predominantly located between the eastern boundary of the rift and two major volcanoes. These fissures are rooted in the deep mantle, where magma doming provides vertical driving forces, while plate separation and extensional tectonics supply horizontal forces. Surface processes, particularly heavy rainfall and subsurface erosion, further exacerbate fissure propagation and hazard potential.
        We propose a novel mechanism for ground fissure development, integrating mantle upwelling, magma intrusion, plate extension, and surface water-driven expansion. This framework advances the theoretical understanding of fissure formation and provides practical insights to enhance infrastructure resilience and community safety in rift regions.
 

ground fissure,mantle plume,EARS,formation mechanism,geological hazard