Assessment of permafrost distribution maps in the Hindu Kush Himalayan region using rock glaciers mapped in Google Earth

Schmid, M.-O.; Baral, P.; Gruber, S.; Shahi, S.; Shrestha, T.; Stumm, D.; Wester, P.

doi:https://doi.org/10.5194/tc-9-2089-2015

Articles | Volume 9, issue 6

https://doi.org/10.5194/tc-9-2089-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/tc-9-2089-2015

© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 9, issue 6

Research article

|

11 Nov 2015

Research article |

| 11 Nov 2015

Assessment of permafrost distribution maps in the Hindu Kush Himalayan region using rock glaciers mapped in Google Earth

M.-O. Schmid, P. Baral, S. Gruber, S. Shahi, T. Shrestha, D. Stumm, and P. Wester

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Final revised paper (published on 11 Nov 2015)
Supplement to the final revised paper
Preprint (discussion started on 15 Oct 2014)
Supplement to the preprint

Interactive discussion

Status: closed

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

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- Supplement

RC C2189: 'Review', Anonymous Referee #1, 30 Oct 2014
- AC C2937: 'Final response', Marc-Olivier Schmid, 21 Jan 2015
RC C2423: 'Comments available in attached file', Lukas U. Arenson, 24 Nov 2014
- AC C2938: 'Final response', Marc-Olivier Schmid, 21 Jan 2015
RC C2424: 'major revision', Anonymous Referee #3, 24 Nov 2014
- AC C2939: 'Final response', Marc-Olivier Schmid, 21 Jan 2015

Peer-review completion

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

AR by Marc-Olivier Schmid on behalf of the Authors (21 Jan 2015) Author's response Manuscript

ED: Reconsider after major revisions (24 Jan 2015) by Tingjun Zhang (deceased)

AR by Marc-Olivier Schmid on behalf of the Authors (24 Jan 2015) Author's response Manuscript

ED: Reconsider after major revisions (07 Feb 2015) by Tingjun Zhang (deceased)

ED: Referee Nomination & Report Request started (18 Mar 2015) by Tingjun Zhang (deceased)

RR by Anonymous Referee #3 (30 Mar 2015)

Suggestions for revision or reasons for rejection

It is well known that permafrost must exist where as active rock glaciers are developed, because there must be permanent ground ice within active rock glaciers. It is said that the regions with active rock glaciers can be absolutely identified as permafrost regions. So the most important question is how to identify active RGs from similar landforms? I thought that this question was not well answered.
1. The authors stated that the identified landforms were true as two persons gave the same classification. I thought that the reliability is just two third if we absolutely believe these two persons were right. Why is it right for two from three? I do think it is still not enough even though all three persons have the same decision. So, RGs mapping by more persons or more evidences are needed to prove the mapping method is right as if no more field evidence.
2. The authors answered the previous question-how to identify the active RGs from RGs, in their responses, but it is still not clear in the context of the manuscript. So we hardly believe your RGs are active or not.
3. From Fig. 6, we could find that the numbers of “RGs” is at same level accompanied with the changing PZI. It is said that the RGs could be found in any regions with any possibility of permafrost existence. So, how to explain “termini of rock glaciers local-scale indications for the presence of permafrost, frequently occurring at an elevation indicative of the lowermost regional occurrence of permafrost in mountains (Haeberli et al., 2006)”? Furthermore, are the regions with PZI from 0 to 0.2 the lowermost regions of permafrost distribution? I thought the PZI is just possibility, but does not mean “real permafrost”, but active RGs are “permafrost”.
4. In the conclusion, your findings are well agreed with PZI, but not IPA map. Does it mean the PZI map is better? Or it is the real permafrost map? Otherwise, what did you want to conclude?
So my suggestion is to rewrite the manuscript as rock glaciers distribution in this study region, and firstly, to find more evidence to make the readers to believe that your RGs are real rock glaciers and real active rock glaciers; secondly, find more regularity of RGs in this region, its relationship with elevation, slope, and even climate condition.

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RR by Kenneth HEWITT (31 Mar 2015)

Suggestions for revision or reasons for rejection

Regrettably I cannot recommend publication.

I realize a lot of work has gone into this and the topic is timely. The authors have cleared up most of the minor points raised by reviewers, including mine. However, there are no satisfactory changes or improvements in the main argument and fundamentals. There was no ‘major revision’.

Perhaps there is no way to address the basic weaknesses of the methods applied. The results remain unconvincing. What is meant by a ‘first order’ assessment, and why this is so called, is not clear. There is not, and probably could not be, a substantial or reliable ‘assessment of permafrost maps in the (‘mountainous parts’) of the HKH…’ from the data presented. It anything, it seems likely to distort rather than improve knowledge of permafrost distribution.

Questionable assumptions about the nature of rock glaciers, and what they might tell us, remain. For instance, it continues to be asserted that they ‘…often lie near the lowermost regional occurrence of permafrost in mountains…” What ‘often’ means is still unexplained. As reviewers noted, the great majority of known RGs in the region, including termini, DO NOT lie at or near the lowermost limit of permafrost. Many reach below it, and most may terminate at higher elevations, partly for reasons raised in review.

I remain unconvinced that the evidence presented can or does distinguish reliably between active, inactive and ‘fossil’ RGs, or parts of them (in Fig. 2 for example).
In sum, the approach still seems confused; the results, or assertions based on them, confusing. There may be a case for further discussion but, without new avenues, I doubt it. I can imagine ways in which this study might be built upon, tested, perhaps refined, but that is up to the researchers concerned not a reviewer. For the present, publication in Cryosphere, without substantial new work, could send the wrong message on this.

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ED: Reconsider after major revisions (04 Apr 2015) by Tingjun Zhang (deceased)

AR by Marc-Olivier Schmid on behalf of the Authors (23 Jun 2015) Author's response Manuscript

ED: Referee Nomination & Report Request started (02 Aug 2015) by Tingjun Zhang (deceased)

RR by Anonymous Referee #4 (12 Aug 2015)

Suggestions for revision or reasons for rejection

I have read this manuscript with great interest, along with the review comments and the responses by the authors. However, but I like the approach and consider this as a very valid contribution to understand permafrost distribution in large and more or less inaccessible areas, and actually to check the validity of numerical models. I also admit having a “euro-centric” view on this matter, and I also see the problem of transferring this other areas, however, in my opinion this is justified in this case. I also see that reviewers ask to use models to check the validity of the RG inventory; however, it should be vice versa, as the authors also did in the manuscript. The discussion boils down to some major questions:

1. Are RG good indicators for PF? I think a large part of the scientific community working with this topic will answer a clear yes.

2. Is a RG inventory something scientific valuable publishable in the Cryosphere? I again think, yes, at least a large and significant work as done here.

3. Does such a RG inventory indicate the quality or validity of modeling approaches? Again, yes. The IPA map is a “manually” drawn map, the map is good at places where there has been good observations, and very limited to useless other places. The scale of which this map was produced makes it more or less useless for mountain areas. So it is no surprise that the RG inventory from this study differ quite a lot from the IPA map boundaries. The PZI is based on a quantitative independent approach, and has of course also its limitations. But future approaches will follow similar lines, including re-analysis data, remote sensing data etc., and these approaches will normally have a better resolution than the IPA map. Here, the result of this study will be a very valuable data set.

4. Is the identification of RG from GoogleEarth reliable? Well, here one can of course have a large discussion. I think the authors give a good description of how they identified the RGs, they made an extensive manual. There are certainly misinterpretations; however, the data set is statistically large enough to justify the observed pattern.

5. Are RG related to permafrost limits? This is now thoroughly discussed in the manuscript. Often, and in steep mountains, they may show lower limits, because RG produce a cool anomaly in relation to the surrounding because of air convection in the course blocky material. But this is of course not the case everywhere, and there may be processes in these central-Asian mountains, which are not known or good investigated, and which may counter-act this assumption.

This in mind, I have some minor comments to the manuscript. I understand the reviewers that the manuscript is partly hard to follow, especially for an audience not familiar with the topic:

• First of all, I think the discussion and conclusions should be separated, it is better to combine results and discussion, and then give clear conclusions in some points. So I would move discussions points from chapter 6 to the results, rename the chapter to “results and discussion” and finally give clear conclusions. Maybe also the “Background” chapter to a large degree could be a discussion. I mean, you give an introduction, which is quite lengthy, then a lengthy background, and then you start methods. This is probably one reason the paper is hard to follow. Consider revising, but maybe it is better this way, so you should check that at least.

• Chapter 7 I would remove out of the main manuscript and include before, after or inside the acknowledgement.

l. 43: Reference there maybe to some general publication, e.g. IPPC or similar
l 57: “e.g.” Bolch, there are several
l. 145: Please give an explanation why RG forms a sort of “thermal anomaly”
l. 186 ff. This could be also moved in to a discussion section
l. 216: Again, a discussion point

In conclusion, the authors for the first time provide an inventory of RG distribution over a vast area in central Asia. RGs are the only visible expression of mountain permafrost, thus this information is very valuable for validating former and future modeling exercises of permafrost in high-mountain areas. With that, this paper should be published, maybe after addressing some of the minor comments.

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RR by Robert Kenner (02 Sep 2015)

ED: Publish subject to minor revisions (Editor review) (08 Oct 2015) by Tingjun Zhang (deceased)

AR by Marc-Olivier Schmid on behalf of the Authors (30 Oct 2015) Author's response Manuscript

ED: Publish subject to technical corrections (03 Nov 2015) by Tingjun Zhang (deceased)

Short summary

The extent and distribution of permafrost in the mountainous parts of the Hindu Kush Himalayan (HKH) region are largely unknown. This article provides a first-order assessment of the two available permafrost maps in the HKH region based on the mapping of rock glaciers in Google Earth. The Circum-Arctic Map of Permafrost and Ground Ice Conditions does not reproduce mapped conditions in the HKH region adequately, whereas the Global Permafrost Zonation Index does so with more success.