Theoretical Stability of Ice Shelf Basal Crevasses with a Vertical
Basal crevasses threaten the stability of ice shelves through the
potential to form rifts and calve icebergs. Different existing fracture
theories lead to distinct calving predictions. Furthermore, it is
important to determine the dependence of crevasse stability on
temperature due to large vertical temperature variations on ice shelves.
In this work, we explore the transition from basal crevasses to full
thickness fractures considering the vertical temperature structure.
Nye’s Zero-Stress approximation violates Newton’s second law. By
upholding horizontal force balance, it has been shown analytically that
the threshold stress for rift initiation is that of a freely-
floating unconfined ice tongue. We generalize the force balance argument
to show that while temperature structure influences crack depths, the
threshold rifting stress is insensitive to temperature. In the classical
Nye’s theory, basal crevasses would develop into rifts at a stress twice
of that in our Nye’s theory adhering to horizontal force balance.