NISAR observations of contracting dike-driven crustal deformation during the 2025 Hayli Gubbi Eruption, Afar

The November 2025 eruption at Hayli Gubbi volcano in the Danakil Depression, Afar, represents the first opportunity to leverage newly operational NISAR data for investigating magmatic processes during active continental rifting. Here, we integrate NISAR and Sentinel-1 SAR datasets with satellite optical imagery to characterize surface deformation and constrain the source parameters driving the eruption. Our analysis reveals a summit caldera collapse at Erta Ale and the formation of new collapse pits and radial-circumferential fissures at Hayli Gubbi. By combining left-looking NISAR and right-looking Sentinel-1 observations, we produce a complete three-dimensional co-eruptive deformation map, from which we infer two shallow tensile dislocation models representing segmented contracting dikes beneath Erta Ale’s dual calderas. These magmatic structures were active during prior eruptions, implying they are persistent magmatic structures facilitating magma transport beneath the volcano. Our findings demonstrate how spatially partitioned magmatic systems drive rift-related volcanic activity in the Erta Ale segment.