Abstract ID: 28.7283 | Withdrawn | Requested as: Talk | TBA | TBA

Crevasses are critical components of the cryo-hydrologic system. The Continuum Damage Mechanics (CDM) framework has emerged as a promising approach for modeling crevasse fields. However, its application relies on poorly constrained parameters, such as the critical stress threshold, and by the lack of consensus on appropriate stress invariants that should be considered for fracture initiation (the so-called damage criterion). Studies based on observations notably face uncertainties in converting observed strain or strain rate into stress estimates. In this study, we use a carefully monitored artificial drainage event of a water-filled cavity on the Tête Rousse Glacier in 2010 to investigate fracture initiation processes, focusing on refining damage criteria and stress thresholds. Using the finite element code Elmer/Ice, we simulate the drainage and subsequent refilling of the cavity over three consecutive years. The simulated stress distributions are compared to a field of circular crevasses that were mapped around the cavity during the summer following the first drainage operation. Our results show that stress patterns derived from a non-linear viscous mechanical response (i.e., Glen’s flow law with n = 3) better match observed crevasse fields than those assuming a linear viscous or a linear elastic mechanical behavior. Furthermore, by evaluating four commonly used damage criteria in glaciology-related applications —maximum principal stress, von Mises, Hayhurst, and Coulomb— we show that the maximum principal stress criterion, paired with a stress threshold of approximately 100 to 130 kPa, provides the best reproduction of the observed crevasse field.