Understanding the mechanisms underlying subcritical crack growth in shales is vitally important but data available to date have been scarce. Chandler et al.  provide a significant amount of real-time observations on shales during loading. One of the applications is the assessment of the long-term stability of clayrocks including caprocks and source rocks in sedimentary basins. In addition, this work underlines the role of subcritical crack growth in rocks during the evaluation of the safety of long-term stability of geological storage structures.
Citation: Chandler, M. R., Fauchille, A.‐L., Kim, H. K., Ma, L., Mecklenburgh, J., Rizzo, R., et al. . Correlative optical and X‐ray imaging of strain evolution during double‐torsion fracture toughness measurements in shale. Journal of Geophysical Research: Solid Earth, 123. https://doi.org/10.1029/2018JB016568
—André Revil, Editor, JGR: Solid Earth