Glacier damage evolution over ice flow timescales

Ranganathan, Meghana; Robel, Alexander A.; Huth, Alexander; Duddu, Ravindra

doi:https://doi.org/10.5194/tc-19-1599-2025

Articles | Volume 19, issue 4

https://doi.org/10.5194/tc-19-1599-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/tc-19-1599-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 4

Research article

|

23 Apr 2025

Research article |

| 23 Apr 2025

Glacier damage evolution over ice flow timescales

Meghana Ranganathan, Alexander A. Robel, Alexander Huth, and Ravindra Duddu

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Final revised paper (published on 23 Apr 2025)
Supplement to the final revised paper
Preprint (discussion started on 09 Aug 2024)
Supplement to the preprint

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2024-1850', Anonymous Referee #1, 31 Oct 2024

See supplement.

Citation: https://doi.org/10.5194/egusphere-2024-1850-RC1
- AC1: 'Reply on RC1', Meghana Ranganathan, 09 Dec 2024
  
  The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1850/egusphere-2024-1850-AC1-supplement.pdf
  
  Citation: https://doi.org/10.5194/egusphere-2024-1850-AC1
RC2:
'Comment on egusphere-2024-1850', Anonymous Referee #2, 10 Nov 2024

Please see attached pdf

Citation: https://doi.org/10.5194/egusphere-2024-1850-RC2
- AC2: 'Reply on RC2', Meghana Ranganathan, 09 Dec 2024
  
  The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1850/egusphere-2024-1850-AC2-supplement.pdf
  
  Citation: https://doi.org/10.5194/egusphere-2024-1850-AC2

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

ED: Publish subject to revisions (further review by editor and referees) (12 Dec 2024) by Carlos Martin

AR by Meghana Ranganathan on behalf of the Authors (16 Jan 2025) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (22 Jan 2025) by Carlos Martin

RR by Anonymous Referee #1 (18 Feb 2025)

Suggestions for revision or reasons for rejection

I would like to thank the authors for their thorough response to both my main concerns and smaller comments. I believe that the revisions made to the manuscript will help the readers better understand the proposed damage model and its implications (e.g., plotting Figure 2 for a 1000-year simulation).

As I previously commented, I believe the SSA limits the realism of the current model since it does not account for velocity and stress distribution over the ice column, and consequently, cannot capture vertical advection of damage. These limitations are acknowledged in the discussion, and I understand that this is beyond the initial scope of this work, which aims to introduce “a simple damage model to simple ice flow models.” Using a higher-order model and comparing the results with the SSA would be an interesting follow-up study, which the authors seem to have considered, and which I look forward to read!

Upon- re-reading the manuscript, I came across the following sentence, and I would be interested to hear the authors’ thoughts on it:

“The loss of load-bearing capacity in a continuous region across the ice shelf means that downstream ice transmits no buttressing stress upstream, thus representing the dynamic effect of calving on the remaining ice, even in the absence of explicitly simulated iceberg detachment. Some damage also accumulates in the margins near the grounding line and in the center of the ice shelf.”

I am not suggesting that this be discussed in the manuscript, but I wonder: for a model like yours, there do you think there is little need to explicitly simulate a proper calving front (like in CalvingMIP for example)? Since most of highly damaged areas, which should calve, have almost no impact on upstream flow?

Technical suggestions:

Line 383: typo “cressvassing”  “crevassing”
Line 443: “to to”
Line 587: The ice sheet model icepack uses the Shallow-Shelf Approximation (SSA), which calculates depth-averaged flow fields […]

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ED: Publish subject to technical corrections (18 Feb 2025) by Carlos Martin

AR by Meghana Ranganathan on behalf of the Authors (19 Feb 2025) Author's response Manuscript

Short summary

The rate of ice loss from ice sheets is controlled by the flow of ice from the center of the ice sheet and by the internal fracturing of the ice. These processes are coupled; fractures reduce the viscosity of ice and enable more rapid flow, and rapid flow causes the fracturing of ice. We present a simplified way of representing damage that is applicable to long-timescale flow estimates. Using this model, we find that including fracturing in an ice sheet simulation can increase the loss of ice by 13–29 %.