Alu-Dalafilla

Geography & Climate

Alu-Dalafilla is located in Ethiopia, within the Afar Rift Volcanic Province of the broader Eastern Africa Volcanic Regions. Situated at 13.79° N, 40.55° E in the Northern Hemisphere, the volcano lies within a tropical climate zone. With a summit elevation of 578 meters above sea level, Alu-Dalafilla is a moderately sized peak that remains accessible to hikers and researchers for much of the year. The volcanic landform is characterized as a cluster, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Alu-Dalafilla is situated along a rift zone, where tectonic plates are pulling apart. As the crust thins and fractures, magma rises to fill the gap, creating volcanic activity. Rift volcanism typically produces more fluid lava flows rather than explosive blasts, which means communities near Alu-Dalafilla in Ethiopia generally face slower-moving hazards like lava flows and ground fissures rather than sudden pyroclastic events. However, rift volcanoes can still generate significant ash emissions and gas releases that affect local air quality. The dominant rock type is basalt / picro-basalt, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Alu-Dalafilla has 1 recorded eruption in the geological database, spanning from 2008 CE to 2008 CE. The most powerful recorded event was a severe eruption capable of regional ash fall and pyroclastic flows in 2008 CE, reaching VEI 3 on the Volcanic Explosivity Index. With eruptive activity as recently as 2008 CE, Alu-Dalafilla remains an actively monitored volcano.

Significance

With a maximum recorded VEI of 3, Alu-Dalafilla has produced eruptions capable of generating pyroclastic flows and significant ash fall in the surrounding area. While not among the largest eruptions globally, VEI 3 events pose serious hazards to local populations and can disrupt regional air travel. Given its recent activity, Alu-Dalafilla is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

The summit region of Alu, ~5 km NW of the Dalafilla stratovolcano, is an ellipsoidal volcanic horst, elongated NNW-SSE, and formed primarily of older basaltic lava flows. Recent fractures along the axis of the Erta Ale range cut the main horst of Alu and areas to the SSE. Fumarolic activity is located on the numerous parallel faults. Fissure vents west of the horst have fed silicic lava flows, and voluminous youthful basaltic lava flows to the east extend north as far as Lake Bakili. Dalafilla, also referred to as Gabuli, is a steep-sided cone that rises 300 m above surrounding lava fields due to extrusion of viscous, silicic lava flows. Basaltic lava flows from regional fissures surround the volcano. Fumarolic activity occurs in the 100-m-wide summit crater and has weathered surrounding lava flows. The first historical eruption of Alu-Dalafilla took place in 2008, when lava flows from vents between the two edifices traveled NE.

— Smithsonian Institution, Global Volcanism Program