Nature Communications (Aug 2020)

Cascadia low frequency earthquakes at the base of an overpressured subduction shear zone

  • Andrew J. Calvert,
  • Michael G. Bostock,
  • Geneviève Savard,
  • Martyn J. Unsworth

DOI
https://doi.org/10.1038/s41467-020-17609-3
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 10

Abstract

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Regions of the subducting oceanic crust are often considered to be overpressured, owing to fluid trapped beneath an impermeable seal along the overlying inter-plate boundary. Here, the authors show that slow slip earthquakes at the Cascadia subduction zone occur immediately below a 6-10 km-thick shear zone, in which slab-derived fluids are likely trapped at near-lithostatic pore pressures.