Dear Matthias Rode and co-authors,
Your manuscript received 3 detailed reviews that were very critical and consistently raised some major issues with this manuscript. The was one additional independent comment.
The referees and comment noted that a wide range of data are presented with some interesting results and they saw general the relevance of the topic of mountain permafrost distribution interaction under the ongoing retreat of glaciers, and that as such the manuscript would be in the scope of the TC journal.

However, the referees consistently identified the following issues/weaknesses
-limited general quality of the manuscript (scientific analysis and discussion limited and not elaborate enough, English language should be improved,…)
-limited datasets to be conclusive (only a few month of temperatures)
-interpretation and conclusions to vague and not well supported by collected evidence (e.g. permafrost degradation hard to conclude from data)
-aim and focus of study not that clear, clarification of link of permafrost part to glacier retreat required as most interesting/novel.
-many smaller issues such as figures should be made more readable and more details to methods and results added.

In view of these issues and the general critical comments from the referees this manuscript would need very substantial revisions and I have my doubts that the authors would achieve to address all the raised issues within a reasonable time, in particular as some of the issues are related to limitations in datasets which probably can not be completely changed.
However, from the response of the authors it seems that the authors already undertook such substantial revisions and may be ready in due time to submit a revised version.

If the authors think their revised manuscript addressed the major (and minor) issues raised by the referees I invite them to submit such a manuscript, but it is hard to judge from the rather brief and general response to judge how well the authors addressed the reviews. Depending on the quality and improvements of the Thus, I can not guarantee that the manuscript will not be rejected before another round of thorough reviews.

I briefly summarise the most important points that I certainly expect to be addressed:

-clarify focus and aim of study (what is novelty/gap addressed, relevance for wide/international audience; note that the glacier retreat interaction with permafrost distribution is really the crucial, novel and exiting part and just a paper on local permafrost distribution is not enough for TC).
-improve discussion and interpretation of results (more detailed/careful/substantiated and more focused, better structured analysis/discussion; in particular of ERT and temperatures )
-make sure conclusions are well supported by presented data/results and significant
-improve readability of figures
-correct/add small details in the methodology and better motivate/justify selection of site/methods
-improve English language and readability of figure
-address in detail (and comment in response line by line) all major and minor comments of the referees.

Andreas Vieli, editor
28 July 2019

Dear M. Rode and co-authors,
I apologies for the delay in making a decision on this manuscript. First of all, it was difficult to find a referee for a re-review, so that I decided at the end to do a thorough review of the manuscript myself (editors review) which is integrated below this decision letter. This review took then far longer than I anticipated, partly because the revisions seemed to be done somewhat sloppy (editing issues etc., inconsistent labelling/numbering etc., see re-review below) and in the response document it was difficult at times to follow what changes/revisions have specifically been undertaken (a track changes document with everything red, as entire sections have been shifted, does really not help!).

The revised manuscript addressed most of the major issues raised in the first round of reviews, in particular the focus and aim, the discussion and conclusions and some details in methodology and site selection have been improved.
In the current manuscript the focus is now much clearer on the investigation of permafrost in formerly ice covered rock-wall areas which are, given the widespread recession of glaciers, also interesting for the wider cryosphere research community and makes as such this study really novel. This clarified focus on permafrost in the deglaciated area is now also well reflected in the much improved discussion.
The multi-observational approach is now also well explained, motivated and the uncertainties well evaluated. Further, the analysis and the interpretation is now more differentiated and the conclusions in line with and supported by the presented evidence.

However, there are still a couple of points that need to be addressed for before potential acceptance of this manuscript for publication:

1) Abstract: although the main focus on the investigation of permafrost in the area of a recently retreated ice margin is in the main manuscript now much clearer, unfortunately this focus does not come out well in the abstract, as the abstract remains largely unchanged. Thus the abstract needs to be revised and better aligned with the revised main focus of the manuscript (see also specific comments below).

2) Significance/relevance: although the discussion has been strongly improved and is more focused, the discussion is still somewhat limited with regard to significance (wider meaning, impact, transferability, link to existing literature,…) and the wider relevance could perhaps still be improved. Significance and impact are important criteria for acceptance in TC and thus strengthening the manuscript with regard to significance (e.g. maybe add a small paragraph in the discussion in this respect) essential.

3) with regard to the discussion and interpretation there are in my view still some open points (make comparison to Boeckli model more clear/relevant; clarify classification 'possible' and 'probable and its relevance; is 'polythermal' glacier state necessary for degradation interpretation (b); etc… see specific points below).

4) imprint of ice cover in permafrost distribution pattern: with regard to the question of formation of the permafrost (aggregation/degradation?) below the formerly ice covered area, I agree that more (and longer-term) investigation are required (which is rightly a relevant conclusion). However, as indicated in the discussion there is evidence for both, but this could be made clearer in the conclusions.
Further and importantly, there is a clear imprint from the former ice cover in the permafrost distribution pattern (ERT in particular transect K1 and K3). This should really be made much clearer in the discussion and conclusions (and maybe even be included in the abstract). This may also help to take away the focus from the somewhat inconclusive question of aggregation versus degradation (which I understand can with the given the collected evidence not be fully resolved).

3) writing, editing issues and labelling: although, some of the minor writing and language issues have been addressed, quite a few editing issues remain (inconsistencies in labelling) and with the revisions the numbers in figure referencing in the text are muddled up (which really did not give me the impression of a 'careful' revisions). All these issues and other minor specific points (see list below) should be addressed.

If these general issues above and the more specific points below are addressed carefully, I see the potential for the manuscript to be accepted for publication.
Please also very carefully proof-read any revised version and be as specific as possible in your response of 'how' you addressed these comments and on the revisions undertaken.


More specific points from editors re-review

Discussion aggregation/degradaton:
What I find striking in the ERT-data in particular of the profiles crossing the LIA margin (K1 and K3) is that one seems to see a clear imprint of the former LIA ice margin. The resistivities below and above and the pattern along the profile are significantly different. I think this should be stressed somewhere in the results (4.2) or at the beginning of the discussion 5.3 and maybe even be part of the conclusions.
So strengthen the discussion around this pattern and occurrence of permafrost above and below the LIA line and not only focus on the origin/formation (aggregation versus degradation) of the permafrost below the LIA margin. The novelty of this study is that evidence of permafrost below formerly glaciated margin has been detected, but also that there is in the resistivity pattern a clear imprint of this former margin (and say what this pattern shows).
What is also important to say is that there is clear still clear evidence of permafrost above the LIA margin (irrespective whether it is degrading or not).
Then the discussion on aggregation or degradation should follow (similarly as already done), but this should very carefully consider the observed patterns and evidence (in particular ERT-K1 and K3).

Interpretation: Just a potential consideration with regard to interpretation (a) or (b): What about an alternative interpretation (c) (that is in between (a) and (b)): There could be some permafrost (through transvers heat conduction, ice cleft cooling, blow out erosion…) below the marginal LIA ice cover with no cold based marginal ice and not necessarily any degradation.
The discussion could potentially also consider the potential timescales involved in building up or degrading permafrost of such thickness (literature, perhaps Magnin???).

Abstract: needs to be thoroughly revised in order to align it with the focus and findings/conclusions of the revised manuscript (investigation/detection of permafrost in since LIA deglaciated rockwalls, potential aggregation/degradation). Currently in the second paragraph the general conclusions of permafrost distribution are described with no link to glacier retreat/deglaciation what so ever. It seems the abstract still reflects the conclusions of the first (un-revised) manuscript version. The abstract should really reflect what has been done, found and concluded in the whole study, which it is currently not.

Figure references in text: from about page 5 onwards the figure numbers refered to in the text are mostly wrong, probably as figures have been shifted in the revisions but not properly adjusted the references in the text. This made it very hard to follow the text!
p. 5 line 20: should probably be Fig 5 and/or 2 and NOT Fig 4.
p. 6 line 2: should probably be Fig 3 and NOT Fig 2.
p. 7 line 3: should probably be Fig 3 and NOT Fig 2.
p. 7 line 12: should probably be Fig 3 and NOT Fig 2.
p. 7 line 36: should probably be Fig 3 and/or 5 and NOT Fig 2.
p. 8 line 21: should probably be Fig 3 and NOT Fig 2.
p. 8 line 39: should probably be Fig 4 and NOT Fig 3.
… and likely elsewhere.
Further there seems to be the wrong numbering for table 2 and 1, table 2 comes currently before table 1!
Check all figures reference numbers in text and the table numbering!

Labelling/abbreviations: The used notation in labelling of the different sites is inconsistent (between figures, text and tables) and should be carefully revised throughout, for example:
-In Fig 3 the sites use a hyphen between MS and the site letter (e.g. MS-K), whereas in Fig 5 it is an underscore (e.g. MS_K).
-The ERT profiles in Fig. 5 are suddenly labelled with 'lowercase' letters (e.g. ERT-k2) instead of capital letters as elsewhere in text and table 1 (ERT-K2).
-Further, I do not see why the ERT lines for the sites H, D and G need any numbers (e.g. ERT-D1) as there is only 1 profile per site. Only for site K numbering makes sense.

Figures with subfigures: it would be helpful (and it is common practice) if in figures with subfigures, sublabels would be added (e.g. a) b) c)…) and integrate/reference them into the captions. this applies in particular for figures 4(a,b), 5(a-h), 7(a-f)

Units ERT: Even though some software show the units of the ERT results as [Ohm.m] I see no good reason why, in the main text, there should be a fullstop between Ohm and m; the units simply are [Ohm m]! should be corrected throughout the text.

The BTS results are not shown anywhere except as summary directly in the text, I would somewhere expect a table of all these results (maybe in supplements if there is not enough space), so the evidence is clearly noted somewhere.

p. 2 line 8: here and maybe later in the discussion some literature on temperature conditions in bergschrund may potentially be relevant (for example Sanders et al. (2012) Periglacial weathering and headwall erosion in cirque glacier bergschrunds. GEOLOGY, v. 40; no. 9; p. 779-782; doi:10.1130/G33330.1

p. 2 line 24: make clearer here that you focus these investigation on the recently deglaciated area… this is the novelty of your study, thus has to be really clear.

p. 3 first line: avoid repetition: 'These air temperature conditions indicate the possible …' the

p. 3 line 9-11: starting your sampling strategy of measuring in areas of high permafrost probability seems somehow to defeat the whole purpose of the study! I would start with 'recently deglaciated areas' (above and below, and along within) as the main selection criteria for the sites and then continue with…'within area of expected permafrost'.

p. 4 line 9: style: 'melted down' refers to vertical thinning but you mean area and length retreat, maybe say: '…Schladming Glacier reduced by 55% in area and 48% in length.'

p. 5 and p. 6: table 2: wrong numbering, I think this should be table 1

p. 5 line 20: refer to fig. 1 at end of sentence: '…horizontal recession amounts to 15-30m (Fig. 1).'

p. 6 line 13: delete the space between -3 and 'degree symbol'.

p. 7 lined 19-21: this threshold of -3 C in the WEqT needs a reference of who figured/stated this out (ideally other than from the BTS method).

p. 7 line 22-24: the RD and MD are here introduced and later marked in fig 5 but it is not clear why they are introduced here and in what way this information helps to make the argument/interpretation. Other than marking them in Fig 5 there are later never used in the results/discussion/interpretation. also how are they defined (criteria for classification)?

p. 8: eqn (1) is not really well integrated into the text and just suddenly stands there. I would move it up and integrate it on p. 8 line 7 where the DOI is introduced in the text.:
'…was used (…Stiegler et al. 2014) which is given by
Then add eqn 1
Then it is also clearer why the variables m1, m2, m01 and m02 are introduced in the text (currently above eqn 1).

p. 9 line 5: I would be more specific in saying that you mean GST here and that a WEqT was 'reached': 'The GST observations from January….show that a winter equilibrium temperature … was reached at all sites.'
The sub-sentence on RD and MD can probably be left out, as is not used at all afterwards, and that the RD and MD can be read out of the data is not surprising.
Note that for MS-H the RD seem much too late as the temp start to rise well before (around mid april similar to other sites).

p. 9 section 4.1: here the results of the GST and BTS of Fig 5 are described but the permafrost occurrence 'classes' given in fig. 5 ('probable' and 'possible') are never mentioned in the text here, nor in the discussion and it is not really clear what this classification is referring to. The 'probable' and 'possible' should be integrated/commented here and be clearly defined somewhere what is meant (or leave it out).

p. 9 line 14: for consistency, use oC rather than K (Kelvin).

p. 10 and p. 11: table 1: wrong numbering, I think this should be table 2

p. 10 caption of table 1: use consistent date format: e.g. 05-09 to 09-09-2013 as on page 7 line 4-5.

p. 12 line 7: with 'outermost' I guess you mean 'near surface' layers. Clarify.

p. 13 line 6: be more specific: 'along the CURRENT upper glacier margin'

p. 13 line 8: what do you mean with 'save' MS-G? excluding MS-G? Clarify.

p. 14 line 1-2: this sentence on GST increase trend over time is perhaps also relevant in the context of section 5.3 (degradation/aggregation).

p. 14 paragraph lines 5-11: regarding the fit to the boeckli (2012) model: 'what' exactly fits quite well, which results, what variables? His modelled GSTs, what do they say in comparison to yours. I kind of struggle to see the argument here, do you mean his general tendencies/effects of exposition etc… are consistent with your observed permafrost distribution. If so this seems pretty obvious and boeckli is not the first. Have you applied the boeckli-model quantitatively (produced a map?), then compare to this, if not, this paragraph seems to me rather vague and basically repeats the generally expected exposition effect. Anyway, better argue/explain this comparison.
Further note: how does boeckli treat such ice marginal or formerly ice-covered permafrost areas?

p. 14 line 10: typo: remove full stop between 'conditions' and 'for'.

p. 14 line 8-9: this sentence on the importance of site MS-H for touristic infrastructure, remove or move somewhere else into a better/more relevant context (perhaps in a paragraph on relevance…?).

p. 14: lines 12-18: the increasing active layer depth below the LIA margin and the generally higher resistivities above LIA margin (and increasing active layer depth towards current margin) and lower below the LIA margin is a very interesting and important observation and seems to me crucial for the later interpretation in 5.3 (degradation/aggregation). Based on this evidence, i think one can almost reject interpretation (b) of degradation of permafrost that is buried below the margin of the POLYTHERMAL glacier in the LIA.
This does however, not necessarily mean that all permafrost has aggregated since the LIA there; permafrost may have been there already (cooling through heat conduction, marginal ice cleft, blow out depression…) but that the glacier does not necessarily have to be cold-based there. Maybe differentiate the discussion a bit more.

p. 15 line 18: '…recently deglaciated…' or '...in rockwalls that became recently ice free.'

p. 15 discussion 5.3 on aggregation versus degradation: The distinct imprint of the LIA margin in the resistivity profiles (in particular K1 and K3) should be mentioned/integrated here better (see general more comments above).

p. 15 line 30: if (b) was right I would expect stronger degradation above the LIA line, or am I wrong?

p. 15 line 24: is polythermal really necessary? You could have temperate ice but the permafrost reaching in through heat conduction in the ground transversely under the marginal ice. Or is this too far in?

p. 15 line 31: '…profiles have presumably been ice free…'

p. 15 bottom/16 top: this paragraph referring to magnin and permafrost degradation refers to the general case of permafrost (and not recently deglaciated areas) and maybe should be presented earlier as an external outer boundary condition/setting for the discussion of the degradation case. Also what are the timescales involved for these degradation trends in the modelling by magnin? Decades, centuries???

p. 16 line 8: '….mapping and have delivered VALUABLE information…'

p. 16 line 12-13: this evidence of degrading permafrost should be already used to ague in the discussion (5.3) before.

p. 16 line 17-19: given the evidence this conclusion could probably be formulated somewhat stronger and be better linked/supported by own observations, e.g. along the lines of:
although there is evidence for both degradation and aggregation, considering all evidence aggregation cannot be excluded. However, longer-term observations are required to….

Table 2: style: 'decline' is not that appropriate in first column, maybe say 'Horizontal recession' and 'Vertical thinning' as in caption.

Figure 5:
-add labels to subfigures (a,b,….h) and adjust caption accordingly.
-throughout: write MS-LETTER and not MS_LETTER.
-it is not clear which i-Button is where located, maybe label them in site photographs below.
-how are 'probable' and 'possible' defined (and why not refered to/used in text/discussion?).
-marked RD time in MS-G seems too late (or what is criteria to move it there?).
-caption: add line labelling in caption text: 'The position of the glacier surface (gs; black hatched line)…' and 'The white dashed lines mark the ERT profiles'.
-are the marks for RD and MD really needed, they are not used anywhere in the interpretation. If they are relevant, then use them in your argument.

Figure 6: I am pretty confused why the horizontal ERT profiles are displayed upside down (depth goes up!), it would be easier to read the plots if the surface is at the top.
It would be helpful to mark K1, K2 and K3 more clearly/bold, one really has to go into the small print of the figure to see which one is which profile.

Dear M. Rode, A. Kellerer-Pirklbauer and co-authors,
Thank you for your thorough revisions and response after my in depth re-view after the first round of revisions.

All major and minor issues have been well addressed and it has clearly been documented how and what has been changed (thank you).
In the revised version:
-the abstract reflects now well the focus and main contribution of the paper,
-the significance of the research and results has been much improved,
-the interpretation/discussion is now much more differentiated, clear and well aligned with the evidence presented,
-the imprint of the LIA ice margin in the ERT has been made clearer
-the issues in writing, labelling, editing have been well addressed

There remain a few editing issue and minor points which are listed below and have to be addressed before final acceptance for publication.

I appreciate the very careful consideration of the review-points and very detailed response and thanks the authors for handling this last round of revisions so well.
The editor Andreas Vieli, 16 Feb 2020


Minor technical changes:
(the line numbers refer to the newest revised manuscript)

-Corresponding author: I take form the latest revised version that the corresponding author has changed, which is of course ok, but the aouthors should probably inform the TC-system as well on this change.

-p. 1 line 19: I assume this sentence takes reference to the own observed temperature data, if so better say,: 'According to our ground temperature…'

-p. 1 line 36: add an 'a': '…1975-2000 and a further 10%...'

-p. 2 line 13: style, 'results' is more appropriate here than 'effects'

-p. 6 line 8: something wrong with this sentence (: do you mean '…approach consisting of/including continuous ground surface….'

-p. 7 line 8: add an 'a': '… at each point until an constant….'

-p7 lines 13-15: something wrong with this formulation, the given time periods should be the other way round (the measurement date is in the time period of increase), maybe write something along the lines of…:'The date of the measurements (20-03 and 21-03 2013), falls within a period of generally increasing snow cover as recorded at …..'

p. 7 line 19: something wrong with the brackets: '(iButtons….Integrated)'

p. 7 line 33: remove the quotation mark at the end of the line.

p. 7 line 35/36 and fig 5: just to be clear, the RD is when the warming up by snow melt towards the 0dgerees starts and not when the zero curtain starts to be measured? This is what is indicated by the RD arrows in Fig5. But then the sentence is not quite correct as the RD is not exactly at the beginning of the zero curtain but sliughtly before. Or should the arrows be later in Fig 5a and c? just make it consistent.

p. 8 line 16: add an 'a': '…means of a Wenner array…'

p. 8 line 18: style 'with an enhancement factor'…

eqn 1: replace comma after the equation by a full stop.

p. 8 line 25: remove 'usually' as already used in sentence above.

p. 8 line 32: '…the modelling process has been continued…

p. 8 line 33: maybe better say: '…data sets converged towards similar ….'

p. 8 lines 37-38: too many 'used' here: '…the results of a small-scale….station investigating rock moisture and frost weathering nearby the ERT-profiles …. were used to….'

p. 9 line 4: 'Consistent with the laboratory results of …'

p. 10 line 2: 'This implies big difference in thermal conditions…'

Fig. 6: The headings within the figure should be with a dash ('-') rather than an underscore ('_') e.g. ERT MS-D not ERT MS_D.
Also adjust this in the caption for MS-H

p. 14 line 15: remove the full stop after 'kohm m'

p. 14 line 37: there is one full stop too much here.

p. 15 line 19-20: '…of permafrost in rockwalls recently becoming ice free.'

p. 15 line 37: '… can form within a few years…'

Acknowledgments: please acknowledge the referees in the acknowledgments.