Subspace tear
From Memory Alpha, the free Star Trek reference
A subspace tear is a dangerous and turbulent subspace anomaly which can be created by an isolytic burst, a result of the unpredictable nature of subspace weapons.
In 2375, the Son'a created a subspace tear in the Briar Patch after firing an isolytic weapon at the USS Enterprise-E. The tear threatened to engulf and destroy the Enterprise and as a result Commander Will Riker ordered the ship's warp core to be programmed for a breach and ejected. The tear acted as a magnet, pulling the ejected warp core towards it before it breached, sealing the tear and allowing the Enterprise to escape. (Star Trek: Insurrection)
