Methods and related systems are described for use with hydraulic fracturing and other oilfield applications. A tool body is positioned in a wellbore at a location near a subterranean rock formation being fractured. The tool body contains a plurality of deployable continuous fibers. At least some of the deployable continuous fibers are deployed into fractures within a subterranean rock formation. Each deployed fiber is continuous from the tool body to the rock formation. The number of deployable continuous fibers provides sufficient redundancy to make at least a target measurement relating to the fracturing process.