The 2024 Fentale Diking Episode in a Slow Extending Continental Rift

Dikes can contribute to rifting, but the space-time behavior and role of magma in young and slowly extending continental rifts is unclear. We use InSAR and seismicity during the 2024 Fentale intrusion in the Main Ethiopian rift (MER) to understand magma-assisted rifting at slow extension rates (5 mm/yr). From 2021 to mid-2024, the Fentale Volcanic Complex (FVC) uplifted up to 6 cm. From mid-September 2024, upper crustal diking started northwards along the rift, initially with subdued seismicity. From late-September to early November, dike opening increased to ∼2 m and propagated a total of ∼14 km north, causing increased seismicity from normal faulting. The dike made ∼90% of the total geodetic moment, with the rest from faulting. The character of the event is similar to rifting episodes at mid-ocean ridges and demonstrates that episodic diking can occur in young, slow extending continent rifts but must be more infrequent.