Corbetti Caldera

Volcano number:221290
Region:Africa and Red Sea
Country:Ethiopia
Geodetic measurements?Yes
Deformation observation?Yes
Measurement method(s):InSAR
Duration of observation:1994-2000, 2004-2010
Inferred cause of deformation:Magmatic
Characteristics of deformation:

There is evidence for several periods of uplift and subsidence at Corbetti since 1994, all in a circular pattern centred on the volcano, measured by InSAR (Biggs et al., 2011). Between 1994 and 1996 uplift of 1.4cm was observed. Then between 23 September 1997 – 13 September 2000 a minimum of 14 cm subsidence (incoherence prevents determination of upper bound). Uplift is then observed again in 2009, but lack of data constrains how this develops through time. Between these periods of activity no ground motion is observed where data is available.

The 1997-2000 deformation can be described by point source at a depth of 5.8-7.8 km (to 1 sigma). Comparison of the temporal evolution at Corbetti to Campi Flegrei (Italy) has lead to suggestions that the volcanic processed are independent of the regional stress regime (Biggs et al., 2011).

Inside Corbetti Caldera there are also two peaks (Urji to the west, and Chabi east). The 1997-2000 uplift is centred on Chabi, and the 2009-2010 subsidence is centred between the two peaks.

Further work on the deformation at Corbetti is currently underway by Lloyd et al.

Reference:Biggs, J., I. D. Bastow, D. Keir, and E. Lewi (2011), Pulses of deformation reveal frequently recurring shallow magmatic activity beneath the Main Ethiopian Rift, Geochem. Geophys. Geosyst., 12, Q0AB10, doi:10.1029/2011GC003662
Reference:Siebert, L., and T. Simkin (2002), Volcanoes of the World: An Illustrated Catalogue of Holocene Volcanoes and Their Eruptions, Global Volcanism Program Digital Inf. Ser., GVP‐3, Smithsonian Inst., Washington, D. C. [Available at http://www.volcano.si.edu/world/.]
Location:38.43, 7.18

Time series of deformation at Corbetti volcano, as well as other nearby volcanoes, from Envisat interferograms between 2004 and 2010. Orange highlights show periods of uplift, green highlights subsidence (Biggs et al., 2011).

Interferograms used in the analysis of deformation. Each fringe represents 2.8 cm of displacement in the satellite line-of-sight (Biggs et al., 2011). The summit of the volcano is shown by a black dot, as reported by the Smithsonian Database (Siebert and Simkin, 2002).