From the White Wolf Wiki, the most complete White Wolf reference

Eruption is the short process in which a normal human is changed into a Nova. Usually in times of great stress, the Mazarin-Rashoud Node activates and opens the body of the soon-to-be Nova to vast quantities of Quantum energies. The sheer ammount of power is too great for a normal human to comprehend and in nanoseconds he forms this raw potentional into set "powers" that he can comprehend more easily. These powers are usually something he needs to survive or overcome his highly traumatic and dangerous situation.