This RO contains the VEM code, and the application to the 2011-2012 unrest at Santorini volcanic complex. VEM is a code to model the temporal variation in the volume change of a magmatic source surrounded by a viscoelastic shell. The code computes the ductile deformation of a concentric viscoelastic shell surrounding a shallow magma chamber, driven by separate increases in pressure. The viscoelastic model consists of a magma chamber located at a depth, d, beneath the surface, with a radius R1. The magma chamber is surrounded by a
viscoelastic shell of radius of R2-R1 and rigidity mu, embedded in an elastic half-space. The code is written in Mathematica. For further documentation refer to Parks et al., Journal of Geophysical Research, doi: 10.1002/2014JB011540, 2014.