A Space-time fracture was a fracture in spacetime. This anomaly was associated with temporal distortions.
In 2375, temporal distortions fractured spacetime throughout the USS Voyager. Force fields were erected but had little effect. If not stopped within two hours, the fractures would tear the ship apart. Commander Chakotay later reported to Captain Kathryn Janeway that the space-time fractures were growing stronger. As a result, temporal paradoxes were detected throughout the ship. Internal chronometers showed decks 9 and 13 had different times. Time passed more quickly in some parts of the ship and slowed down in others. This explained why food replicated in the mess hall less than an hour beforehand had already spoiled and Janeway's coffee tasted like it was three days old. Janeway responded that she had been working on a way to enhance their containment fields to keep the fractures from spreading.
29th century force-3 temporal disruptors were designed to fracture spacetime within 150 meters. (VOY: "Relativity")