We study the unrest prior the 2012–13 Tolbachik eruption from seismic and GPS data.
We analyzed the earth surface displacement and seismicity before the eruption.
Pre-eruption crustal deformation, seismicity increase and acceleration were detected.
Duration of seismic and deformation anomaly was ~ 4–5 months before the eruption
This 4–5-month anomaly can be considered as a medium-term eruption precursor.