Skip to main content

Table 1 Summary of the physical parameters controlling fault dynamics

From: Frictional and structural controls of seismic super-cycles at the Japan trench

ParameterSymbolMegasplayFrontal prismForearc upper crustForearc basement
Static friction coefficient\(\mu _0\)0.60.30.30.6
Effective normal stress\({\bar{\sigma }}\)20 MPa60 MPa110 MPa110 MPa
Direct-effect parametera\(1\times 10^{-2}\)\(1\times 10^{-2}\)\(1\times 10^{-2}\)\(1\times 10^{-2}\)
Steady-state parameter\(b-a\)\(4.0\times 10^{-3}\)\(8.0\times 10^{-3}\)\(4.0\times 10^{-3}\)\(4.0\times 10^{-3}\)
Characteristic weakening distanceL8 cm8 cm5 mm1 cm
Loading rate\(V_\text {L}\)31 mm/year52 mm/year84 mm/year84 mm/year
Segment widthW21.2 km60 km24 km58 km
Fault dip\(\phi\)15.74\(^\circ\)5.5\(^\circ\)5.0\(^\circ\)10.6\(^\circ\)
ParameterSymbolArc lower crustMantle wedge cornerCold noseUpper mantle
Static friction coefficient\(\mu _0\)0.60.30.60.6
Effective normal stress\({\bar{\sigma }}\)70 MPa20 MPa80 MPa80 MPa
Direct-effect parametera\(2\times 10^{-2}\)\(2\times 10^{-2}\)\(1\times 10^{-2}\)\(2\times 10^{-2}\)
Steady-state parameter\(b-a\)\(-\,8.0\times 10^{-3}\)\(2.0\times 10^{-3}\)\(-\,2.0\times 10^{-3}\)\(-\,1.0\times 10^{-3}\)
Characteristic weakening distanceL10 cm5 mm2.5 cm20 cm
Loading rate\(V_\text {L}\)84 mm/year84 mm/year84 mm/year84 mm/year
Segment widthW11 km44.8 km53.5 km32 km
Fault dip\(\phi\)10.6\(^\circ\)30.0\(^\circ\)30.0\(^\circ\)31.0\(^\circ\)
  1. The model assumes uniform elastic properties with a shear modulus of \(G=30\) GPa, Poisson’s ratio \(\nu =0.25\), and shear wave speed \(V_S=3\times 10^{3}\) m/s. The reference slip velocity is \(V_0=10^{-6}\) m/s