(covers information from several alternate timelines)
A temporal shock wave approaches two Zahl starships
A temporal shock wave, also known as a spacetime shock wave, was a buildup of temporal energy which traveled through the fabric of spacetime.
A temporal rift studied by USS Discovery in the 2250s emited temporal shock waves. (DIS: "Light and Shadows")
The wave front of a temporal shock wave might change history as it propagated. In an alternate timeline, a Krenim weapon ship, constructed by a scientist named Annorax, produced temporal shock waves as byproducts of the temporal incursions it initiated. When the weapon ship eliminated an object from history, a resultant shock wave radiated from the point of the incursion, the wave front altering the timeline of the universe to compensate for the absence of the object from history. This timeline was later negated when, as a result of massive battle damage, a temporal incursion was initiated within the weapon ship itself, resulting in a shock wave that erased it and all of the damage it did to the timeline from history. (VOY: "Year of Hell", "Year of Hell, Part II")