作者: C.E. Seyler , J.D. Kirkpatrick , H.M. Savage , T. Hirose , D.R. Faulkner
DOI: 10.1016/J.EPSL.2020.116413
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摘要: Abstract The mechanical properties of sediment inputs to subduction zones are important for understanding rupture propagation through the accretionary prism during megathrust earthquakes. Clay minerals strongly influence frictional behavior fault gouges, and clay content input materials varies a stratigraphic section as well margins globally. To establish shallow Cascadia zone place results in global context, we conducted high velocity rotary shear experiments on ODP core samples retrieved from sediments (35-45% clay) suite individual species. We compared our compilation published wet gouge, dry intact rock. For each sample type, three trends were identified with increasing normal stress: 1) stress drop ( τ p − s ) increases linearly, 2) characteristic thermal weakening distance D t h decreases power law function except clay-rich 3) fracture energy W b shows no dependence. However, does vary type. Clay-rich gouges under conditions have lowest energy, both is at least an order magnitude lower than estimates rocks. Therefore when lithologies present, they may minimize spatial variations behavior, allowing earthquakes propagate trench. sediments, there little variation between lithologies, but around higher other margins. relative inhibit large amounts earthquake slip dynamic overshoot.