Phase Field Modeling of Cracks in Ice

• Main Authors: Humbert, Angelika, Sondershaus, Rabea, Gross, Dietmar, Müller, Ralf
• Other Authors: Altenbach, Holm, Hohe, Jörg, Mittelstedt, Christian
• Format: Book Part
• Language: unknown
• Published: Springer 2024
• Subjects: greenlandic; Ice Sheet; Ice Shelves
• Online Access: https://epic.awi.de/id/eprint/58200/; https://epic.awi.de/id/eprint/58200/1/PFMinIce.pdf; https://doi.org/10.1007/978-3-031-45554-4_11; https://hdl.handle.net/10013/epic.8eab4d9d-9ed1-4e82-b04b-c1ce153a890c

Calving of iceberg at ice shelves and floating glacier tongues is a poorly understood process, hence a physically motivated calving law is not yet existing. The demands on developing appropriate models for calving is large, as calving rates are needed for large scale ice sheet models that simulate the evolution of ice sheets. Here, we present a new approach for simulating fracture in ice. Our model is based on a finite strain theory for a viscoelastic Maxwell material, as the large simulation time leads to high strains. The fracturing process is simulated using a fracture phase field model that takes into account the elastic strain energy. We conduct simulations for a typical calving front geometry, with ice rises governing the formation of cracks. To represent the stress state adequately, we first conduct a spin-up to allow the viscous contribution to develop before the fracture phase field is computed. The analysis comprises the assessment of the crack path in comparison to observations, the influence of the spin-up, as well as elastic versus viscous strain contributions based on Hencky strain. Additionally, an estimate of released energy based on high resolution optical imagery of a Greenlandic calving front is presented.