A spatial sinkhole is one of a number of hazardous phenomena which can be encountered in chaotic space. A spatial sinkhole can produce a massive amount of graviton shear, increasing the pressure on a vessel's hull to a dangerous level.
Such a phenomenon was encountered by the crew of the USS Voyager in 2375, when they became trapped in a region of chaotic space in the Delta Quadrant. The crew managed to narrowly avoid being destroyed by the phenomenon by moving away utilizing full thrusters. (VOY: "The Fight")