New analysis of the structure of the Ethiopian rift valley

Giacomo Corti and colleagues from the Universities of RomaTre, Southampton and Imperial College, London recently published the results of their study in Tectonics 

The Ethiopian Rift Valley is a classic example of an area where a continent is splitting apart. Here, active volcanism, earthquakes and fracturing of the Earth's surface break continents and form new oceans. In this paper we analyze the shape and size of the faults and fractures combined with the relief and river drainage of the rift valley, in order to interpret which faults control the shape of the rift, and how they have evolved through time. We find that more than half of the rift is defined by a large fault escarpment along the eastern side of the rift, with the western side defined by a gradual slope (an asymmetric rift).  Less than half is a “classical” rift with clear fault escarpments on both sides (a symmetric rift), and we find no evidence for the previously held view of progressive evolution from an asymmetric to symmetric rift. Instead, we find that the morphology of the rift is primarily controlled by the contrasting properties of the rocks beneath the two sides of the rift, with major fault escarpments forming only where the rocks are strong. Surface processes likely amplified the along-axis differences in rift architecture.

 

Open access to the manuscript describing this study is available here:

onlinelibrary.wiley.com/doi/10.1002/2017TC004799/full

 

For further information, please contact Giacomo Corti (giacomo.corti@igg.cnr.it)

 

 

Full reference: Corti G., Molin P., Sembroni A., Bastow I.D., Keir D. (2018). Control of pre-rift lithospheric structure on the architecture and evolution of continental rifts: insights from the Main Ethiopian Rift, East Africa. Tectonics, 37, doi.org/10.1002/2017TC004799