A schematic of the coupled ocean-ice model of rift propagation presented in the paper.
A schematic of the coupled ocean-ice model of rift propagation. The proposed mechanism for rift propagation at rates that are a small fraction of the speeds for brittle ice uncoupled to the ocean involves interactions between the water and ice that slow the rate rifting. Credit: Olinger et al. [2024], Figure 2a
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: AGU Advances

Antarctic ice sheets break off large tabular icebergs through a process called rifting. However, the difficulty of observing such processes in real time means the physics controlling rifts and their propagation are still poorly understood.

Olinger et al. [2024] (see also the Viewpoint, Hudson [2024]) combined before- and after- satellite observations of a rapid episode of rift expansion in the Pine Island Glacier Ice Shelf. They used continuous seismic records to estimate a rifting rate of some 35 meters/second, the fastest yet reported. However, this rate is far slower than theory would predict for brittle ice deformation.

By modeling the ocean-ice system, they were able to demonstrate the role that the ocean played in setting the observed rifting rate. This improved understanding of how rifts operate is important for assessing the vulnerability of Antarctic ice sheets as the planet warms. 

Citations

Olinger, S. D., Lipovsky, B. P., & Denolle, M. A. (2024). Ocean coupling limits rupture velocity of fastest observed ice shelf rift propagation event. AGU Advances, 5, e2023AV001023. https://doi.org/10.1029/2023AV001023

Hudson, T. (2024). Seismic waves used to measure how ice shelf rifting velocity is limited by ocean coupling. AGU Advances, 5, e2024AV001189. https://doi.org/10.1029/2024AV001189

—Sue Trumbore, Editor-in-Chief, AGU Advances

Text © 2024. The authors. CC BY-NC-ND 3.0
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