From The Heretic Knowledge Vault
An uncontrolled blast of magical energy, arising not from a spell but from other magical effects. The one seen in the story so far resulted from Ian Samael's successful fight with the magical construct of Luminosita. Sarine has implied that something like it occurred a few hundred years ago, most likely when the Veracian Church sent Luminosita to knock down the barrier protecting Praenubilus Astu.
An energy blast like this has nasty effects on some of the magical gadgets in the path of the blast. According to Sarine, the elves in Praenubilus Astu are going to have to change out some busted Light Globes and reset clocks as a result of the blast. It also caused a temporary(?) glitch in the Levitation Device that keeps Tsuirakushiti floating. There were probably other consequences that we haven't seen yet.
For a real-world equivalent, check out the Wikipedia article on electromagnetic pulse, in which a nuke plays the role of Ian -- maybe not such a bad analogy, actually.