Unstable vortex

The Kawoosh is the name Samantha Carter has given to the burst of unstable energy eminatning from an activating Stargate. The "kawoosh" is capable of disintegrating virtually anything it touches, including living tissue. The Tok'ra funeral custom has the dead dissolved by the an activating Stargate. If a Stargate is buried, a kawoosh will not form, preventing a link.

The Supergate also creates a kawoosh, but at a much greater intensity. Thus far, it is the only thing known to overwhelm the shields on an Ori battlecruiser.

Trivia
As a running gag, everyone who sees a kawoosh the first time takes a step back.