2007/01/01 by P.G. Talalay, Pavel G. Тalalay, Roger LeB. Hooke · 2 citations
Earth and Planetary Sciences · Environmental Science · Medicine · #Cryospheric studies and observations #Landslides and related hazards #Winter Sports Injuries and Performance
paper · pdf · doi:10.3189/172756407786857794
openalex publication_date 2007/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract The most frequently used relation between ice deformation rate, έ , and stress, ፐ , is the power law, commonly called Glen’s flow law, έ = Aፐ n , in which A is an ice stiffness parameter and n is an empirical constant. A can be estimated from the simple exponential relation where A 0 is a constant independent of temperature; E , commonly called the enhancement factor, depends on ice crystal orientation, impurity content and other factors; Q is the activation energy for creep; R is the universal gas constant; and T is the absolute temperature. Laboratory experiments yield values of A 0 = 9 . 514MPa –3 a –1 for secondary creep. Typical borehole closure experiments then give E ≈ 0 . 16. This low value probably results from the fact that, when deforming into a borehole, ice is subject to stresses that are inconsistent with the preferred orientation of c axes that has developed over many years under a stress configuration with no borehole present. Closure data from Vostok hole 3G yield E ≈ 0 . 7. This higher value may reflect a unique stress environment yielding fabrics that are somewhat better oriented for borehole closure.