An anti-time eruption is a breakdown of the subspace barrier between time and anti-time.
The rupture being sealed.
In a closed alternate timeline, such a rupture was found by the USS Enterprise-D in the Devron system inside the Romulan Neutral Zone. This rupture sent out waves of temporal energy, which caused Geordi LaForge's eye DNA to regenerate, giving him normal sight. Several other crewmembers reported old scars healing, and nurse Alyssa Ogawa's foetus was killed by the revertion. The rupture was caused by the convergence of three inverse tachyon pulses from three time periods at a single point in space, and was sealed by the Enterprise in all three periods covering the anomaly in a static warp shell. (TNG: "All Good Things...")