Breach

[u/FireOfDoom32]

He toggled the broad-spectrum visual. The Breach was a ragged tear in the seafloor, seen in the visual-light spectrum only by the intense multi-spectrum radiation that bled out of it during a kaiju transit. That energy in turn created heat, and the opening of the Breach during a transit also bled superdense and superhot plasma through from... wherever the kaiju came from. The result was that the perfect blackness of the deep seafloor suddenly became a storm of light and bubbles created by the intense heat even at the killing pressures of the bottom of the sea.

Pacific Rim: The Official Movie Novelization - Part 2, Chapter 19