Table 1.

Typical values of the dimensional constants in the model. The ice viscosity is calculated using Paterson’s (1994) recommended value of the flow-law coefficient at 0°C and a stress of 0.6×105 Pa. See text for further explanation.

symbolmeaningtypical value
ρiice density917 kg m−3
ΔρTwtill–water density difference (2.5)103 kg m−3
ρwwater density103 kg m−3
diice depth103 m
Δρwiequation (2.9)83 kg m−3
ggravity9.8 m s−2
kpermeability10−15 m2
ηwwater viscosity1.8×10−3 Pa s
ϕporosity0.4
bsqueeze coefficient (2.18)0.4×10−2 m2 Pa−1 yr−1
cshearing coefficient (2.15)<1
μcoefficient of friction0.6
Δρswequation (2.17)1.6×103 kg m−3
Dsgrain size10−4 m
KMeyer-Peter and Müller coefficient8
Q0meltwater flux103 m2 yr−1
τ*ccritical Shields stress0.05
ϕderivative of ϕ−10−7 Pa−1
ηiice viscosity2×1013 Pa s
τbbasal shear stress (2.31)104 Pa
Sice-surface slope10−3