Azerbaijan, Gebele: 2008-2017

The Gebele cluster is named for the city of Gebele (also known as Qabala and Gabala) in northern Azerbaijan, on the south flank of the eastern Caucasus Mountains. Much of the seismicity in this region is at lower crustal and upper mantle depths but the cluster is restricted to events with focal depths less than about 20 km. The distribution of stations in the area is quite dense and azimuthal coverage is very good. Even so, free depth relocations were problematic, partly because many of the events are quite shallow and also because the terrain (and probably crustal structure) is strongly variable. Manual fitting of depths based on the residuals at near-source and local-distances is quite good however. [...]