Illuminating seafloor faults and ocean dynamics with dark fiber distributed acoustic sensing

Marine observations with optics Placing sensors on the seafloor is difficult, but a sensor network has huge potential for observing processes occurring both below and above the seafloor. Lindsey et al. measured acoustic vibrations collected by attaching a laser to the Monterey Accelerated Research System's subsea optical fiber during a maintenance period (see the Perspective by Jousset). Acoustic waves were monitored by changes in laser light along the cable. The observations from just a few days allowed mapping of an unknown fault system and detection of several dynamic processes in the water column above. Science , this issue p. 1103 ; see also p. 1076