Investigating seismic and aseismic fault motion caused by the 2024-2025 Fentale dyke intrusions in Ethiopia

The faulting caused by dyke intrusions provide a novel opportunity to study the way natural fault systems respond to time-varying changes to the stress field. The recent 2024-2025 Fentale-Dofen dyking episode in the northern Main Ethiopian Rift (NMER) offers a rare opportunity to investigate these processes, as the surface deformation was captured in unusually high spatial and temporal resolution by satellite radar. In our study, we combine Interferometric Synthetic Aperture Radar (InSAR) data from the COSMO-SkyMed satellite, high resolution Digital Elevation Model (DEM), with a catalogue of >150 relocated moderated-sized earthquakes (M4.5-6) to study the spatio-temporal evolution of seismic and aseismic fault slip linked to dyking in the NMER. We focus on an area ~15 km north of the tip of the dyke, where we find fault patches showing both repeated seismic and aseismic slip occurring in close proximity, associated with surface deformation of