Fig. 8: Elastic parameters of basal marine ice (ISU-5) derived from the Hashin–Shtrikman (H-S) bounds.
From: Seawater softening of suture zones inhibits fracture propagation in Antarctic ice shelves
The analysis assumes the presence of a mixture of ice and seawater of varying fractions. Grey areas show the full range of the H-S bounds in dependence of seawater fraction, for a bulk modulus (\(K_{{\mathrm{HS}}}^ +\) in Eq. (2)); b shear modulus (\(\mu _{{\mathrm{HS}}}^ +\) in Eq. (3)); c P-wave velocity; and d S-wave velocity (see ‘Methods’). Solid blue and red lines show the Voigt–Reuss–Hill averages, above which the H-S bounds describe a matrix-supported porous solid. In c, the observed P-wave velocity range of basal marine ice (3264 ± 63 m s−1) implies a seawater fraction of ~2–13%. In d, this seawater fraction range then implies an S-wave velocity range of basal marine ice of 813–1853 m s−1. All velocity calculations assume a density of 915 kg m−3 for meteoric ice and 920–990 kg m−3 for basal marine ice.
