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Modified Von Mises Stress a Robust Predictor of the Spatial Distribution of Ice Slab Crevasse Fields in Greenland.

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Title: Modified Von Mises Stress a Robust Predictor of the Spatial Distribution of Ice Slab Crevasse Fields in Greenland.
Authors: Culberg, Riley1 (AUTHOR) rtculberg@cornell.edu, Lai, Ching‐Yao2 (AUTHOR), MacKie, Emma3 (AUTHOR), McDowell, Ian1 (AUTHOR), Mutter, Ellen1 (AUTHOR)
Source: Journal of Geophysical Research. Earth Surface. May2026, Vol. 131 Issue 5, p1-19. 19p.
Subject Terms: *Glacial crevasses, *Greenland ice, *Glaciology, *Ablation (Glaciology), *Runoff, Stress measurement (Mechanics), Ice mechanics
Geographic Terms: Greenland Ice Sheet (Greenland), Greenland
Abstract: Fractures in ice slabs modulate the mass balance of the Greenland Ice Sheet by routing meltwater into the englacial system. There, it may be stored locally, reducing runoff and increasing surface mass balance, or drain into the subglacial system and influence ice sliding velocities. However, it is unclear how common ice slab fractures are or how their frequency varies across the ice sheet because these crevasses are too narrow to directly observe with most remote sensing systems. Here, we use observations of fractures from half‐meter resolution imagery and surface stresses calculated from remotely sensed ice velocity fields to estimate the tensile strength of ice slabs, and then predict fracture initiation zones from the von Mises stress. Our regionally cross‐validated model achieves a model‐data agreement score of 0.83 ± $\pm $ 0.03 (out of 1), demonstrating that the von Mises stress is a robust operational predictor of the spatial extent of crevasse fields on Greenland's ice slabs. We predict that 53% of the total ice slab area contains at least one crevasse within 250 m, with the most pervasive crevasse fields in marine‐terminating sectors of the ice sheet. Our results suggest that models that treat ice slabs as impermeable likely overestimate high‐elevation surface runoff. Additionally, the availability of meltwater and englacial storage space, rather than fracture propensity, may set the elevation limit for the development of surface‐to‐bed drainage connections in many regions of the ice sheet. Plain Language Summary: Fractures in ice slabs play an important role in Greenland ice sheet mass loss but are difficult to observe in satellite imagery or predict from physical models. This limits our ability to study how fracturing might lead to different patterns of mass loss in different parts of the ice sheet. Here, we train a statistical model with observed fracture locations to predict whether an ice slab is fractured based on the stresses at the ice sheet surface. Our trained model performs well in all regions of the ice sheet where we have observations, demonstrating that a single stress threshold can predict fracturing. We then use our model to predict fracture zones across all of Greenland's ice slabs and find that 53% of the total area is likely to be fractured. This suggests that in many ice slab regions, some fraction of the surface meltwater can drain and be stored under the ice slabs, leading to less mass loss than predicted. However, these fractures may eventually provide pathways for water to drain to the ice sheet bed and change the ice velocity, particularly if surface melting increases and the storage space beneath the ice slabs is depleted in the future. Key Points: The modified von Mises failure criterion captures the spatial extent of fracture zones in ice slabs on the Greenland Ice SheetWe estimate that ∼53% of the GrIS ice slab area is fractured, making ice slabs more permeable at the km‐scale than previously assumedWe predict that fractured ice slabs are most prevalent in marine‐terminating sectors of the ice sheet [ABSTRACT FROM AUTHOR]
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Database: GreenFILE
Description
Abstract:Fractures in ice slabs modulate the mass balance of the Greenland Ice Sheet by routing meltwater into the englacial system. There, it may be stored locally, reducing runoff and increasing surface mass balance, or drain into the subglacial system and influence ice sliding velocities. However, it is unclear how common ice slab fractures are or how their frequency varies across the ice sheet because these crevasses are too narrow to directly observe with most remote sensing systems. Here, we use observations of fractures from half‐meter resolution imagery and surface stresses calculated from remotely sensed ice velocity fields to estimate the tensile strength of ice slabs, and then predict fracture initiation zones from the von Mises stress. Our regionally cross‐validated model achieves a model‐data agreement score of 0.83 ± $\pm $ 0.03 (out of 1), demonstrating that the von Mises stress is a robust operational predictor of the spatial extent of crevasse fields on Greenland's ice slabs. We predict that 53% of the total ice slab area contains at least one crevasse within 250 m, with the most pervasive crevasse fields in marine‐terminating sectors of the ice sheet. Our results suggest that models that treat ice slabs as impermeable likely overestimate high‐elevation surface runoff. Additionally, the availability of meltwater and englacial storage space, rather than fracture propensity, may set the elevation limit for the development of surface‐to‐bed drainage connections in many regions of the ice sheet. Plain Language Summary: Fractures in ice slabs play an important role in Greenland ice sheet mass loss but are difficult to observe in satellite imagery or predict from physical models. This limits our ability to study how fracturing might lead to different patterns of mass loss in different parts of the ice sheet. Here, we train a statistical model with observed fracture locations to predict whether an ice slab is fractured based on the stresses at the ice sheet surface. Our trained model performs well in all regions of the ice sheet where we have observations, demonstrating that a single stress threshold can predict fracturing. We then use our model to predict fracture zones across all of Greenland's ice slabs and find that 53% of the total area is likely to be fractured. This suggests that in many ice slab regions, some fraction of the surface meltwater can drain and be stored under the ice slabs, leading to less mass loss than predicted. However, these fractures may eventually provide pathways for water to drain to the ice sheet bed and change the ice velocity, particularly if surface melting increases and the storage space beneath the ice slabs is depleted in the future. Key Points: The modified von Mises failure criterion captures the spatial extent of fracture zones in ice slabs on the Greenland Ice SheetWe estimate that ∼53% of the GrIS ice slab area is fractured, making ice slabs more permeable at the km‐scale than previously assumedWe predict that fractured ice slabs are most prevalent in marine‐terminating sectors of the ice sheet [ABSTRACT FROM AUTHOR]
ISSN:21699003
DOI:10.1029/2025JF008385