A method of detecting seismic waves traveling through a subsurface formation includes lowering a cable into a borehole in the subsurface formation, the cable having at least one optical fiber associated therewith, and causing descent of a remote end of the cable to be arrested. The method further includes feeding a further length of the cable into the borehole such that the cable is slack and in contact with at least part of a wall of the borehole, and using an interrogator coupled to the at least one optical fiber to detect seismic waves traveling through the subsurface formation and into the cable.