Subspace tear
A subspace tear is a violently destructive phenomenon which can be created as a byproduct of an isolytic burst. Attracted to the energy output of warp cores, such a tear could continue to expand until sealed.

In 2375, the Son'a created a subspace tear in the area of space known as the Briar Patch, through the detonation of an isolytic burst, which they had fired during their attempt to prevent the  from leaving the Patch. The Enterprises warp core acted like a magnet to the tear, causing it to expand. The tear was sealed when Lieutenant Commander La Forge ejected the warp core and detonated it, successfully neutralizing the cascade. ()

See also
Subspace rift
Subspace rupture

de:Subraumriss
ja:亜空間の裂け目
tear