@article{TEXTUAL,
      recid = {10995},
      author = {Wang, Yanbin and Zhu, Lupei and Shi, Feng and Schubnel,  Alexandre and Hilairet, Nadege and Yu, Tony and Rivers,  Mark and Gasc, Julien and Addad, Ahmed and Deldicque,  Damien and Li, Ziyu and Brunet, Fabrice},
      title = {A laboratory nanoseismological study on deep-focus  earthquake micromechanics},
      journal = {Science Advances},
      address = {2017-07-21},
      number = {TEXTUAL},
      abstract = {Global earthquake occurring rate displays an exponential  decay down to ~300 km and then peaks around 550 to 600 km  before terminating abruptly near 700 km. How fractures  initiate, nucleate, and propagate at these depths remains  one of the greatest puzzles in earth science, as increasing  pressure inhibits fracture propagation. We report  nanoseismological analysis on high-resolution acoustic  emission (AE) records obtained during ruptures triggered by  partial transformation from olivine to spinel in  Mg<sub>2</sub>GeO<sub>4</sub>, an analog to the dominant  mineral (Mg,Fe)<sub>2</sub>SiO<sub>4</sub> olivine in the  upper mantle, using state-of-the-art seismological  techniques, in the laboratory. AEs’ focal mechanisms, as  well as their distribution in both space and time during  deformation, are carefully analyzed. Microstructure  analysis shows that AEs are produced by the dynamic  propagation of shear bands consisting of nanograined  spinel. These nanoshear bands have a near constant  thickness (~100 nm) but varying lengths and self-organize  during deformation. This precursory seismic process leads  to ultimate macroscopic failure of the samples. Several  source parameters of AE events were extracted from the  recorded waveforms, allowing close tracking of event  initiation, clustering, and propagation throughout the  deformation/transformation process. AEs follow the  Gutenberg-Richter statistics with a well-defined b value of  1.5 over three orders of moment magnitudes, suggesting that  laboratory failure processes are self-affine. The seismic  relation between magnitude and rupture area correctly  predicts AE magnitude at millimeter scales. A rupture  propagation model based on strain localization theory is  proposed. Future numerical analyses may help resolve  scaling issues between laboratory AE events and deep-focus  earthquakes.},
      url = {http://knowledge.uchicago.edu/record/10995},
}