|Region:||Africa and Red Sea|
|Duration of observation:||2008 - 2010|
|Inferred cause of deformation:||Magmatic|
|Characteristics of deformation:|
In November 2008 an eruption occurred at the Alu-Dalafilla volcanoes, causing lava flows to extend to the NE. Pagli et al. (2012) showed that this eruption was sourced by a 1 km deep elongated magma chamber that exists in two segments, and was probably trigged by an influx of magma from the north. Both magma chamber segments appeared to source the eruption though a connecting dyke. The magma chambers have since, rapidly, refilled.
InSAR was the primary tool to determine deformation during the eruption. Co-eruptive interferograms show an elongated, ~ 10-km-long, subsidence of 1.9 m at the Alu volcano, and at Alu-South, maximum subsidence of 1 m. From 5 November 2008 the deformation pattern at Alu-South reversed and uplift started, whereas at Alu minor subsidence continued between 5th November and 19th November but afterwards reversed to uplift. Since then, uplift occurred both at Alu and Alu-South. The maximum dyke opening to model this observation was 4.6 m and the total dyke volume was 5.1×106 m3. The observation of post-eruptive uplift is interpreted as the refilling of the source magma chamber.
|Reference:||Pagli, C., Wright, T. J., Ebinger, C. J., Yun, S. H., Cann, J. R., Barnie, T., & Ayele, A. (2012). Shallow axial magma chamber at the slow-spreading Erta Ale Ridge. Nature Geoscience, 5(4), 284-288.|
This photograph shows Dalaffilla volcano, a conical edifice at the south of Alu-Dalafilla, as seen from the NW. The 2008 lava flows originated between Alu and Dalafilla and extended to the NE. Copyrighted photo by Marco Fulle, 2002 (Stromboli On-Line, http://stromboli.net).