Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up

Miles, Bertie W. J.; Stokes, Chris R.; Jamieson, Stewart S. R.

doi:https://doi.org/10.5194/tc-11-427-2017

Articles | Volume 11, issue 1

https://doi.org/10.5194/tc-11-427-2017

© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/tc-11-427-2017

© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 11, issue 1

Research article

|

08 Feb 2017

Research article |

| 08 Feb 2017

Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up

Bertie W. J. Miles, Chris R. Stokes, and Stewart S. R. Jamieson

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Final revised paper (published on 08 Feb 2017)
Preprint (discussion started on 14 Jun 2016)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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- Supplement

RC1: 'Review of "Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, and the long-term speed-up of Holmes Glacier"', Allen Pope, 23 Jul 2016
RC2: 'Review of Miles et al., 'Simultaneous disintegration of outlet glaciers in Porpoise Bay....'', T A Scambos, 26 Jul 2016
AC1: 'Combined response to reviewer comments', Bertie Miles, 02 Oct 2016

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Bertie Miles on behalf of the Authors (02 Oct 2016) Author's response Manuscript

ED: Referee Nomination & Report Request started (07 Oct 2016) by Robert Bingham

RR by Allen Pope (15 Oct 2016)

Suggestions for revision or reasons for rejection

In “Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea-ice break-up,” Miles et al. present a study which investigates a few East Antarctic floating ice tongues. Using SAR imagery, they document calving behavior to sea ice concentrations and explain large calving events by relating these observations to atmospheric reanalyses. With these data, they come to the conclusion that large calving events happen during sea-ice break-up events, but there are different conditions which lead to sea-ice break-up.

This paper’s significant revision removes a large section of the paper in order to better focus on two particular calving events in more detail, digging into the mechanisms of their occurrence.

Overall, this is an interesting paper, expanding our knowledge of mechanisms of ice retreat in the Antarctica.

However, I have two specific comments that I believe will improve the paper:
1) The sections which discuss the role that atmospheric anomalies play in the break-up are a little bit difficult for me to follow. I hope the authors consider re-writing the sections so that they are a little easier for the reader to follow. Specifically, use simpler sentences which follow each other and smaller paragraphs each with a defined goal.
1.1) On a related topic, some of this material is repeated in section 5.2. It is hard to tell if this is an oversight or intentional. Please revisit to be sure.
2) While the atmospheric conditions described in the paper are helpful for explaining the break-up events, I believe each requires a little more attention. In particular, prior to the first calving event, atmospheric circulation clearly weakens the sea-ice, when is there a long lag before the break-up event? I think this needs to be better explained. And for the second event, is there any information which corroborates your hypothesis that this is the outer limit of sea-ice stability, except for the repeated location of calving? There are many geographical factors which could explain that.

Further small comments are annotated in the attached PDF.

After these comments are addressed, I recommend this paper for publication in The Cryosphere. --Allen Pope

Referee Report: PDF

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ED: Publish subject to minor revisions (Editor review) (07 Dec 2016) by Robert Bingham

AR by Bertie Miles on behalf of the Authors (13 Dec 2016) Author's response Manuscript

ED: Publish subject to technical corrections (25 Jan 2017) by Robert Bingham

AR by Bertie Miles on behalf of the Authors (25 Jan 2017) Manuscript

Short summary

We observe a large simultaneous calving event in Porpoise Bay, East Antarctica, where ~ 2900 km² of ice was removed from floating glacier tongues between January and April 2007. This event was caused by the break-up of the multi-year sea ice usually occupies the bay, which we link to climatic forcing. We also observe a similar large calving event in March 2016 (~ 2200 km²), which we link to the long-term calving cycle of Holmes (West) Glacier.