Stalling (breakaway of airflow from the convex side of the compressor blade, just behind the leading edge) can also be caused by improper angle position of fixed blades, or more usually by a transient condition during run-up to full compressor load. The surge phenomenon is a momentary flowback from high-pressure (aft end) to low-pressure (forward end) lasting only a few milliseconds, disappearing and returning some milliseconds later, creating a vibration which puts extreme load on blades and shaft. Surge during transient conditions can be avoided by modifying inlet guide vane angle, compressor blow-off valves set to open to atmosphere above a certain pressure, or even cutting off the fuel flow for a split second allowing the compressor to 'jump' from one speed/pressure characteristic curve to another.
I found this elsewhere and can't take credit for the info