Table 1 Friction and fracture parameters used in the simulations

E ₀

Mechanical aperture

1200 µm

Arbitrary (common values) (McClure 2012; Gischig 2015)

σ _Enref

Reference normal traction (mechanical aperture)

25 MPa

E _res

Residual mechanical aperture

2 µm

φ _Edil

Dilatation angle (mechanical aperture)

0°/2.5°/5°

(Willis-Richards et al. 1996; Kohl and Mégel 2007)

e ₀

Hydraulic aperture

120 µm

Arbitrary (common values) (McClure 2012; Gischig 2015)

σ _enref

Reference normal traction (hydraulic aperture)

25 MPa

e _res

Residual hydraulic aperture

0.2 µm

φ _Edil

Dilatation angle (hydraulic aperture)

2.5°

Arbitrary (good coupling)

ρ

Fluid density

1000 kg/m³

Water values at 20 °C

µ

Fluid viscosity

0.001 Pa s

h

Out-of-plane dimension

100 m

To obtain representative magnitudes

η

Radiation damping coefficient

3 MPa/(m∕s)

Arbitrary (common value) (McClure 2012)

S ₀

Cohesion

0 MPa

Assumption

G

Shear modulus

15 GPa

Arbitrary (common value)

ν _r

Poisson’s ratio

0.25

Arbitrary (common value)

f ₀

Nominal friction coefficient

0.85

Arbitrary (common value) (Häring et al. 2008; Gischig 2015)

d _c

Characteristic displacement scale

100 µm

Gouge material (Marone and Scholz 1988; Scholz 2002; Gischig 2015)

a

Velocity effect coefficient

0.01

Scholz (2002)

b

State effect coefficient

0.02

v ₀

Reference velocity

10⁻⁶ m∕s

Arbitrary (common value)

θ _RS

State

2.6·10⁶ s

Rubin and Ampuero (2005); Gischig (2015)

T _str

Matrix tension strength

3 MPa

Arbitrary (common value)(McClure 2014)

K1_crithf

Stress intensity factor

1.5 MPa m^1/2

Arbitrary (common value)(Zeeb and Konietzky 2015; Meyer et al. 2017)