Diverse calving patterns linked to glacier geometry

Bassis, J. N.; Jacobs, Stan

doi:10.1038/ngeo1887

Cited by 129 publications

(156 citation statements)

References 23 publications

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“…consistent with Bassis and Jacobs [2013] who noted that calving is a two-step process consisting of (i) iceshelf rifting that forms an iceberg and (ii) iceberg detachment. The results here suggest that strong (crossshore) winds may be required to drive large tabular icebergs away from their source ice shelves.…”

Section: Journal Of Advances In Modeling Earth Systems 101002/2017mssupporting

confidence: 64%

“…For GCMs with active ice shelves, a calving law is needed to release the tabular iceberg into the ocean. The question of what calving law to use is a topic of ongoing research [Benn et al, 2007;Alley et al, 2008;Levermann et al, 2012;Bassis and Jacobs, 2013] and is still unresolved. One potential way to temporarily bypass this problem would be to run hindcast simulations using historically observed calving events.…”

Section: Journal Of Advances In Modeling Earth Systems 101002/2017msmentioning

confidence: 99%

“…Modeling the collisions and movements of rigid objects precisely requires very small time steps and precise collision detection algorithms, which are very computationally expensive. Models using these methods are typically only run for a few days or even a few seconds, and are used to study rapid processes like crack formation or ridging [Hopkins, 2004;Bassis and Jacobs, 2013;Rabatel et al, 2015]. The tabular iceberg framework presented in this study is developed in order to be used in general circulation models used for multiyear simulations.…”

Section: Interactive Forcesmentioning

confidence: 99%

“…Since the focus of this study is on developing a framework for modeling tabular icebergs, we bypass the question of how to prescribe a physical calving law [Benn et al, 2007;Alley et al, 2008;Levermann et al, 2012;Bassis and Jacobs, 2013] by manually breaking off a semicircular iceberg. This is achieved by allowing all ice elements initially within a 14.4 km radius of the center of the ice front to move freely while the other ice elements continue to be held stationary.…”

Section: Iceberg Calvingmentioning

confidence: 99%

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Modeling tabular icebergs submerged in the ocean

Stern

Adcroft

Sergienko

et al. 2017

J Adv Model Earth Syst

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Large tabular icebergs calved from Antarctic ice shelves have long lifetimes (due to their large size), during which they drift across large distances, altering ambient ocean circulation, bottom‐water formation, sea‐ice formation, and biological primary productivity in the icebergs' vicinity. However, despite their importance, the current generation of ocean circulation models usually do not represent large tabular icebergs. In this study, we develop a novel framework to model large tabular icebergs submerged in the ocean. In this framework, tabular icebergs are represented by pressure‐exerting Lagrangian elements that drift in the ocean. The elements are held together and interact with each other via bonds. A breaking of these bonds allows the model to emulate calving events (i.e., detachment of a tabular iceberg from an ice shelf) and tabular icebergs breaking up into smaller pieces. Idealized simulations of a calving tabular iceberg, its drift, and its breakup demonstrate capabilities of the developed framework.

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Section: Journal Of Advances In Modeling Earth Systems 101002/2017mssupporting

confidence: 64%

Section: Journal Of Advances In Modeling Earth Systems 101002/2017msmentioning

confidence: 99%

Section: Interactive Forcesmentioning

confidence: 99%

Section: Iceberg Calvingmentioning

confidence: 99%

See 2 more Smart Citations

Modeling tabular icebergs submerged in the ocean

Stern

Adcroft

Sergienko

et al. 2017

J Adv Model Earth Syst

View full text Add to dashboard Cite

show abstract

“…Another approach to modelling calving uses discreteelement models (Bassis and Jacobs, 2013;Åström et al, 2013). This type of model has produced interesting results in terms of calving processes and iceberg size distribution.…”

Section: Introductionmentioning

confidence: 99%

Combining damage and fracture mechanics to model calving

et al. 2014

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Abstract.Calving of icebergs is a major negative component of polar ice-sheet mass balance. Here we present a new calving model relying on both continuum damage mechanics and linear elastic fracture mechanics. This combination accounts for both the slow sub-critical surface crevassing and the rapid propagation of crevasses when calving occurs. First, damage to the ice occurs over long timescales and enhances the viscous flow of ice. Then brittle fractures propagate downward, at very short timescales, when the ice body is considered as an elastic medium. The model was calibrated on Helheim Glacier, Southeast Greenland, a well-monitored glacier with fast-flowing outlet. This made it possible to identify sets of model parameters to enable a consistent response of the model and to produce a dynamic equilibrium in agreement with the observed stable position of the Helheim ice front between 1930 and today.

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Structural and environmental controls on Antarctic ice shelf rift propagation inferred from satellite monitoring

et al. 2013

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[1] Iceberg calving from ice shelves accounts for nearly half of the mass loss from the Antarctic Ice Sheet, yet our understanding of this process is limited. The precursor to iceberg calving is large through-cutting fractures, called "rifts," that can propagate for decades after they have initiated until they become iceberg detachment boundaries. To improve our knowledge of rift propagation, we monitored the lengths of 78 rifts in 13 Antarctic ice shelves using satellite imagery from the Moderate Resolution Imaging Spectroradiometer and Multiangle Imaging Spectroradiometer between 2002 and 2012. This data set allowed us to monitor trends in rift propagation over the past decade and test if variation in trends is controlled by variable environmental forcings. We found that 43 of the 78 rifts were dormant, i.e., propagated less than 500 m over the observational interval. We found only seven rifts propagated continuously throughout the decade. An additional eight rifts propagated for at least 2 years prior to arresting and remaining dormant for the rest of the decade, and 13 rifts exhibited isolated sudden bursts of propagation after 2 or more years of dormancy. Twelve of the fifteen active rifts were initiated at the ice shelf fronts, suggesting that front-initiated rifts are more active than across-flow rifts. Although we did not find a link between the observed variability in rift propagation rate and changes in atmospheric temperature or sea ice concentration correlated with, we did find a statistically significant correlation between the arrival of tsunamis and propagation of front-initiated rifts in eight ice shelves. This suggests a connection between ice shelf rift propagation and mechanical ocean interaction that needs to be better understood.Citation: Walker, C. C., J. N. Bassis, H. A. Fricker, and R. J. Czerwinski (2013), Structural and environmental controls on Antarctic ice shelf rift propagation inferred from satellite monitoring,

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Diverse calving patterns linked to glacier geometry

Cited by 129 publications

References 23 publications

Modeling tabular icebergs submerged in the ocean

Modeling tabular icebergs submerged in the ocean

Combining damage and fracture mechanics to model calving

Structural and environmental controls on Antarctic ice shelf rift propagation inferred from satellite monitoring

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