A Short-Time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (Case Study: Scottbreen, SW Svalbard)

Round 1

Reviewer 1 Report

Dear Editor,

A fine contribution to the rapid morphological changes that took place in the period of study, thanks to the very high level of precision measurements of the terrain, and a good explanation concerning the causes of such changes. I only have a few minor editorial remarks in my notes to the authors.

have a few remarks, purely editorial:

Fig.1(A) items 1-7 are not readable, please redress.

Fig.2 legend units should be larger

Line 220  “to 6 mm (at distances of 4 mm) at a distance … “  This is not clear to me.

Table 1  glacier type: letter l is missing in supraglacial

207 DoD is used for the first time, but explanation follows only a sentence later.

Line 436  “thickest fraction”? – probably coarsest fraction

Line 437  “  The coarse-grain fraction material which is being eroded feeds the river’s sediments load, nevertheless, it is only transported at small distances..” Why not simply : Dislodged pebbles and boulders feed the sediment load of the river but are transported over small distances only  …

445  “cutting plains” How can plains cut?

446  “fault zones” Not clear to me ; faults within the ice or what?

458  “an …processes”  Singular and plural together?

511  … glacier has undergone

Author Response

Response to the suggestions and comments of the Reviewer #1,

We are grateful to the Reviewer for their tremendously helpful comments regarding the proposed version of the article resources-992800 entitled ‘A Short-time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (case study: Scottbreen Glacier, SW Svalbard)'. We attempted to consider all of the Reviewers’ and Editors’ comments and remarks in order to adjust the text to the requirements of Resources Journal.

General changes to the text

1. The title was reedited and changed; the new title is ‘A Short-time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (case study: Scottbreen, SW Svalbard)’
2. All figures was reedited according to Reviewers’ comment
3. The entire Table 2 has been moved to ‘Supplementary files’ as ‘Appendix 1’.
4. References were verified and supplemented
5. The text has been redrafted and shortened where possible. The meteorological description has been reworded to remove unnecessary information and moved to ‘Results’ chapter. The section has been reduced to include information that is most relevant in explaining the phenomena described in the glacier foreground during the period under review. A selection of better matched terms was made, in line with and according to the Reviewer’s suggestions. The entire text of the manuscript was corrected and improved. English language content was carefully proofread following the Reviewers’ suggestions by a native English speaker, Luke Boczkowski.

All comments and suggestions contained in the review have been taken into account.

Response to general comments and suggestions for Authors (Reviewer #1):

R#1: A fine contribution to the rapid morphological changes that took place in the period of study, thanks to the very high level of precision measurements of the terrain, and a good explanation concerning the causes of such changes. I only have a few minor editorial remarks in my notes to the authors.

A: Thank you for all the useful feedback. All comments and suggestions have been included in the revised version of the manuscript.

Response to specific comments:

R#1: Fig.1(A) items 1-7 are not readable, please redress.

A: The figure was redrawn. The markings in the legend have been enlarged.

R#1: Fig.2 legend units should be larger

A: The figure was redrawn. The markings in the legend have been enlarged.

R#1: Line 220  “to 6 mm (at distances of 4 mm) at a distance … “  This is not clear to me.

A: The position accuracy (3D = 6mm) takes into account the angular deviation, therefore it is less than the distance measurement accuracy (2D=4mm). The accuracy of the position is more important for the study, so the second parameter (distance) has been deleted.

R#1: Table 1  glacier type: letter l is missing in supraglacial

A: Corrected to ‘supraglacial’.

R#1: 27 DoD is used for the first time, but explanation follows only a sentence later.

A: The term ‘DEM of Difference’ and the ‘DoD’ acronym was used for the first time in line #9 (first sentence of the abstract). Nevertheless, according to the Reviewer's suggestion, the full description of 'DEM of Difference (DoD)' was used in the first reference in the introduction.

R#1: Line 436  “thickest fraction”? – probably coarsest fraction

A: Word ‘thickest’ replaced by ‘coarsest’

R#1: Line 437  “  The coarse-grain fraction material which is being eroded feeds the river’s sediments load, nevertheless, it is only transported at small distances..” Why not simply : Dislodged pebbles and boulders feed the sediment load of the river but are transported over small distances only  …

A: The sentence rewritten as suggested by the Reviewer:  ‘Dislodged pebbles and boulders feed the sediment load of the river but are transported over small distances only ‘

R#1: 445  “cutting plains” How can plains cut?

A: Phrase 'cutting plains' replaced by 'zones of thrust faults'

R#1: 446  “fault zones” Not clear to me ; faults within the ice or what?

A: This means the fault zones in glacial ice go transversely to the longitudinal axis of the glacier, then they lead to the sediments deposition.

R#1: 458  “an …processes”  Singular and plural together?

A: Deleted ‘an’ before ‘intensive’

R#1: 511  … glacier has undergone

A: Throughout the text (including the title), the name of the glacier is reduced to Scottbreen. Scottbreen=Scott Glacier. So Scottbreen glacier would be a redundancy because in Norwegian ‘breen=glacier'

Yours sincerely,

Waldemar Kociuba

Author Response File: Author Response.docx

Reviewer 2 Report

The materials presented in the manuscript are quite interesting and they are worth getting acquainted with by polar and alpine researchers in different study fields. But, at the same time, the paper requires additional work of the authors to improve it.

It is not well structured enough. For example, the "Methods" section does not specify where and how the weather observations were made. It does not contain any information about the frequency and accuracy of observations on ablation stakes, the results of which suddenly appear in the discussion section (but not in the Results, where they should have been).

The text in general is quite loose and can be shortened without compromising the content.

The text needs to be edited to make it clearer, more precise, and more specific. For example, phrases like this (lines 353-355): “The lifespan of these 'ephemeral landforms' depends on the adaptation to the new functioning conditions and the polygenesis of the morphodynamic processes”. - can be written simpler, clearer, and shorter. I have no way of pointing out every such place in the text, but I think that unnecessary and  inaccurate words and phrases is a serious flaw.

It should also be checked and corrected by a native-English speaker (including a terminology check)

Now, some specific comments , but some of them, please,  take into account as also relevant to the entire paper.

Line 23 and 29: repletion of the same text

Lines 24-27: a long list of all landforms is not necessary

Lines 41, 44 and 46: it seems to me that giving such references  (all in a row to three dozen publications) is not productive and does little to understand the essence of the scientific problem discussed in the introduction.

Lines 52-54:  dGPS/GNSS and rtkGPS/GNSS methods allow to measure not only horizontal component (as authors state), but all components of glacier movement

Lines 61-65:  I do not agree with the two linked statements (1) that the accuracy 0.05-0.01 m in measurements of glacier tongue movement is a low one, and therefore (2) that the dGPS/GNSS and rtkGPS/GNSS method gives only a very general idea of this movement. I think that this accuracy is high enough to have rather clear knowledge on glacier tongue movement.

Lines 73-74: only photogrammetric analysis of stereo-pairs of air photo is discussed. Ground-based (terrestrial) photogrammetry is not mentioned and compared here with other methods.

Line 100: is not clear what is meant by the term “multidimensional estimation” of changes. Why subtraction of two 3D models will result in multidimensional estimation?

Line 133, Figure 1B: there are two outlines (and polygons) near southern part of glacier terminus that are not explained in captions.  When did the glacier cover these two areas? Indicate the time in legend or some where else.

Line 133, Figure 1B: Three colored boxes with numbers 1,2,3 in the legend under this figure have no explanations in figure caption.

Lines 138-139, Table 1:  Information on glacier volume (km3) ca. 0.5 (1990) is outdated. Ice volume is estimated as 0.38±0.301 km3 (2009) in: Navarro F.J., Martín-Español A ., Lapazaran  J.J., Grabiec M., Otero J., Vasilenko E.V. , Puczko D. Ice Volume Estimates from Ground-Penetrating Radar Surveys, Wedel Jarlsberg Land Glaciers, Svalbard. - Arctic, Antarctic, and Alpine Research, 46(2):394-406 (2014). https://0-doi-org.brum.beds.ac.uk/10.1657/1938-4246-46.2.394

Lines 138-139, Table 1: information on zero changes of ice thickness (m) in accumulation area (>350 m a.s.l.)  is wrong. Simple comparison of the Savlbard map 1990 (https://toposvalbard.npolar.no/) with ICESat-2 data shows large changes in accumulation area above 350 m a.s.l. For example, for point 77.54077°N 14.33759°E  in accumulation area the difference of 1990 map and  ICESat-2  (2 January 2019, Track ID 76, Segment 432048, Beam gt3l, Product ATL 06 - EGM2008-adjusted) shows that the glacier has become -18 m thinner (0.62 m yr-1).

Lines 138-139, Table 1: misprint - “supraglacia”should be “supraglacial”

Line 140: “The study was performed in the area spanning 205,388 m2…” in Table 3 it is  205389 m2.

Line 145: “… an area of 62,321 m2…” but Table 3 shows different value. It means the numbers should be checked throughout the text.

Line 172, Figure 2: specify the date on which the glacier outline is shown.

Lines 173-175: Check the caption! It does not correspond to the map. Point 3) is repeated twice. 'Glacier' is repeated two times... Ridges (1) do not belong to "the actively transforming glacier’s forefield zone" etc.

Line 184: the section 2.2. Meteorological conditions can be shortened. All relevant information is presented on Figure 3 and might be explained in one sentence.

Line 200: misprint - “trifold” should be “threefold”

Line 255: correct the sentence “…2013 after the 3-day heavy rainfall which was caused by 3-day heavy rainfall due to…”

Line 274: Throughout the text the terms "area" and "surface area" are used but never - planar area. It is necessary to clarify what exactly the authors understand by the "area" and "surface area" - planar or surface area?

Lines 293, Table 2: the table shows 74% for “Thresholded DoD Estimate” in third line (Total area). If I understand correctly, it means that 26% of total area are stable (with <0.02m difference). And, if so, why the stable area (as a separate unit) and its pattern is not analyzed and discussed in this paper? It looks at least very strange.

Lines 293-297, Table 2: the table is too cumbersome and difficult to understand. Lines with "Total volume of difference.." and "Average total thickness of difference ..." are redundant. The table content is already overloaded.

Line 305-306: “…the character of the Scottbreen’s terminus surface lowering was polygenetic”. It would be better to be more specific and clear. What exactly is the polygenetic nature of surface lowering? Ice ablation and..?

Lines 321 and 445: does it mean that the thrust (by 1 m up) occurred in 21 days on glacier terminus ?

Line 329 Figure 5: the color scale on Figure 5 is pleasant to look at, but does not help in any way to see the details of the surface change on the maps. Shadowed DEM background also interferes with this.

Line 331: “…major contours every 5 m; minor contours every 0.25 m.”  contour lines are absent or not visible on Figure 5.

Line 338: sentence “…a number of new landforms have been mapped as a result of the glacier's front retreat…” is not perfectly accurate. Better to say that a number of new landforms created by glacier were mapped.

Line 389: The possibility that the subsidence in some parts of this zone might be the result of thawing of frozen ground or buried ice is not considered. It is not possible or..?

Line 413: I do not find in this section the real discussion of numbers presented in Table 2. For example, Table 2 shows for the glacier forfield (D) the total net volume difference as +5596 m3 on total area 87880 m2. It means +6.37 cm per 21 days or +3 mm/day. What is the density of sediments? Is it possible to compare these rates with other observation ?  etc.

Line 466: where is pole no.2? Is it the same as SC2 or..?

Lines 474-477:  When it  was another above-average precipitation episode (which occurred at the end of the ablation season)?  - give the dates.

 Lines 474-477: As I understand the area lowering - 0.75 m at SC1 was registered by direct measurements of the ablation stake from July 10th to August 18th (21 days), and in the same period  the average area lowering by DoD is -1.1-1.5m. I have three questions: (1) what is the size of spot where the average area lowering by DoD is -1.1-1.5 m and where this spot is located ?  Why the difference of stake measurement and DoD results is so large? Why you do not provide the results (Table) of ablation stake measurements?

Line 526: here is an example of a non-specific verbiage.

Author Response

Response to the suggestions and comments of the Reviewer #2,

We are grateful to the Reviewer for their tremendously helpful comments regarding the proposed version of the article resources-992800 entitled ‘A Short-time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (case study: Scottbreen Glacier, SW Svalbard)'. We attempted to consider all of the Reviewers’ and Editors’ comments and remarks in order to adjust the text to the requirements of Resources Journal.

General changes to the text

1. The title was reedited and changed; the new title is ‘A Short-time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (case study: Scottbreen, SW Svalbard)’
2. All figures was reedited according to Reviewers’ comment
3. The entire Table 2 has been moved to ‘Supplementary files’ as ‘Appendix 1’.
4. References were verified and supplemented
5. The text has been redrafted and shortened where possible. The meteorological description has been reworded to remove unnecessary information and moved to ‘Results’ chapter. The section has been reduced to include information that is most relevant in explaining the phenomena described in the glacier foreground during the period under review. A selection of better matched terms was made, in line with and according to the Reviewer’s suggestions. The entire text of the manuscript was corrected and improved. English language content was carefully proofread following the Reviewers’ suggestions by a native English speaker, Luke Boczkowski.

All comments and suggestions contained in the review have been taken into account.

Response to general comments and suggestions for Authors (Reviewer #2):

A: Thank you for all the useful feedback. All comments and suggestions have been included in the revised version of the manuscript.

R#2: The materials presented in the manuscript are quite interesting and they are worth getting acquainted with by polar and alpine researchers in different study fields. But, at the same time, the paper requires additional work of the authors to improve it. It is not well structured enough. For example,

1) the "Methods" section does not specify where and how the weather observations were made.

A: Information about meteorological conditions was reworded. 1) The description of meteorological conditions in the examined period was moved to ‘the results’ section. 2) In the 'method' chapter, sections describing the methodology of meteorological measurements were added

2) It does not contain any information about the frequency and accuracy of observations on ablation stakes, the results of which suddenly appear in the discussion section (but not in the Results, where they should have been).

A: As above, information about glaciological measurements has been added to the method chapter

3) The text in general is quite loose and can be shortened without compromising the content.

A: Substantial parts of the text have been reworded and shortened

4) The text needs to be edited to make it clearer, more precise, and more specific. For example, phrases like this (lines 353-355): “The lifespan of these 'ephemeral landforms' depends on the adaptation to the new functioning conditions and the polygenesis of the morphodynamic processes”. - can be written simpler, clearer, and shorter. I have no way of pointing out every such place in the text, but I think that unnecessary and  inaccurate words and phrases is a serious flaw.

A: The whole text has been thoroughly revised in order to improve its English language constructions, to standardise terminology and to clarify the content.

5) It should also be checked and corrected by a native-English speaker (including a terminology check)

A: Proofreading by English native speaker has been re-performed.

Response to specific comments:

R#2: Line 23 and 29: repletion of the same text

A: Duplicate text was deleted

R#2: Lines 24-27: a long list of all landforms is not necessary

A: List of landforms was removed

R#2: Line 23 and 29: repletion of the same text

A: Duplicate text was deleted

R#2: Lines 41, 44 and 46: it seems to me that giving such references  (all in a row to three dozen publications) is not productive and does little to understand the essence of the scientific problem discussed in the introduction.

A: Verified list of references – kept five references to the most relevant and best suited papers

R#2: the differential global positioning system (dGPS/GNSS) or the real time kinematic GPS (rtkGPS/GNSS)

A: Removed 'the differential global positioning system (dGPS/GNSS)' is - kept only the one used in this study i.e. rtk-GNSS

R#2: Lines 61-65:  I do not agree with the two linked statements (1) that the accuracy 0.05-0.01 m in measurements of glacier tongue movement is a low one, and therefore (2) that the dGPS/GNSS and rtkGPS/GNSS method gives only a very general idea of this movement. I think that this accuracy is high enough to have rather clear knowledge on glacier tongue movement.

A: 1) it is about the accuracy of 0.05-0.1 m (or 5-10cm), not 0.05-0.01 m (or 1-5cm) as written in the commentary. Generally, we agree. This is not a 'low' accuracy at all. However, even in 2013, the TLS measurements gave an accuracy ten times better than GNSS.

2) Agree comprehensively. However, this was not about the possibility of this system at all, but about its practical application in the case of Scottbreen which is a very slow-moving glacier. On the basis of the d-GPS measurements previously carried out on Scottbreen, only the simplified glacier tongue range in the plane (Zagórski et al. 2004) was determined.

R#2: Lines 73-74: only photogrammetric analysis of stereo-pairs of air photo is discussed. Ground-based (terrestrial) photogrammetry is not mentioned and compared here with other methods.

A: Added information on the use of ground-based photogrammetry (also in studies of the analysed area)

R#2: Line 100: is not clear what is meant by the term “multidimensional estimation” of changes. Why subtraction of two 3D models will result in multidimensional estimation?

A: Agreed. The word "multidimensional" has been deleted.

R#2: 1) Line 133, Figure 1B: there are two outlines (and polygons) near southern part of glacier terminus that are not explained in captions.  When did the glacier cover these two areas? Indicate the time in legend or some where else.

2) Line 133, Figure 1B: Three colored boxes with numbers 1,2,3 in the legend under this figure have no explanations in figure caption.

A: The figure was redrawn. The markings in the legend have been enlarged.

R#2: 1) Lines 138-139, Table 1: Information on glacier volume (km3) ca. 0.5 (1990) is outdated. Ice volume is estimated as 0.38±0.301 km3 (2009) in: Navarro F.J., Martín-Español A ., Lapazaran  J.J., Grabiec M., Otero J., Vasilenko E.V. , Puczko D. Ice Volume Estimates from Ground-Penetrating Radar Surveys, Wedel Jarlsberg Land Glaciers, Svalbard. - Arctic, Antarctic, and Alpine Research, 46(2):394-406 (2014).

A: Content of the table has been corrected and references completed.

2) Lines 138-139, Table 1: information on zero changes of ice thickness (m) in accumulation area (>350 m a.s.l.) is wrong. Simple comparison of the Savlbard map 1990 (https://toposvalbard.npolar.no/) with ICESat-2 data shows large changes in accumulation area above 350 m a.s.l. For example, for point 77.54077°N 14.33759°E  in accumulation area the difference of 1990 map and  ICESat-2  (2 January 2019, Track ID 76, Segment 432048, Beam gt3l, Product ATL 06 - EGM2008-adjusted) shows that the glacier has become -18 m thinner (0.62 m yr-1).

A: Reviewer's suggestion has been taken into account, and the reduction of area for the period of 1990-2019 has been corrected

3) Lines 138-139, Table 1: misprint - “supraglacia”should be “supraglacial”

A: Corrected to ‘supraglacial’.

R#2: Line 140: “The study was performed in the area spanning 205,388 m2…” in Table 3 it is  205389 m2.

A: Corrected to number indicated in the table.

R#2: Line 145: “… an area of 62,321 m2…” but Table 3 shows different value. It means the numbers should be checked throughout the text.

A: Verified to 62,558m² in accordance with the data in the supplementary file ‘Appendix 1B’.

R#2: Line 172, Figure 2: specify the date on which the glacier outline is shown.

A: The figure was redrawn; the date on which the glacier outline is shown was specified. The markings in the legend have been shortened to 5 and enlarged.

R#2: Lines 173-175: Check the caption! It does not correspond to the map. Point 3) is repeated twice. 'Glacier' is repeated two times... Ridges (1) do not belong to "the actively transforming glacier’s forefield zone" etc.

A: The figure was redrawn. The markings in the legend have been corrected. The figure's caption has been rewritten.

R#2: Line 255: correct the sentence “…2013 after the 3-day heavy rainfall which was caused by 3-day heavy rainfall due to…”

A: The sentence has been reworded on ‘The first measurement was made on July 28th, and the next one on August 18th, 2013 following a 3-day heavy rainfall which was caused by an inflow of south-west air masses’.

R#2: Line 274: Throughout the text the terms "area" and "surface area" are used but never - planar area. It is necessary to clarify what exactly the authors understand by the "area" and "surface area" - planar or surface area?

A: Good point. In all instances, simply the term 'area' is used.

R#2: 1) Lines 293, Table 2: the table shows 74% for “Thresholded DoD Estimate” in third line (Total area). If I understand correctly, it means that 26% of total area are stable (with <0.02m difference). And, if so, why the stable area (as a separate unit) and its pattern is not analyzed and discussed in this paper? It looks at least very strange.

A: Thank you for that relevant comment. This is a problem that I have been thinking about for a long time during the calculations and I am convinced that the choice made was correct. It is difficult to justify it in a few sentences and I am going to make a separate short paper (perhaps a letter, which touches on this thread) on this case. So, here is the justification in a few sentences. In GCD analysis the uncertainty was calculated using the minimum level of detection (minLoD) approach while accounting for a uniform error of ~0.02 m., which was rtkGNSS accuracy. This value determined the uncertainty range of the whole survey. However, the application of the measurement methodology made this error practically irrelevant in the DTMs differentiation process. So, 1) The network of reference points (GCPs) was established before the survey. The GCPs points (0.7 m long wooden stakes embedded in the ground to a minimum depth of 0.5 m, with the fixed and marked centre point) were permanently embedded in stable landforms and their position was determined by means of rtkGNSS with accuracy (>0.02m); 2) GCPs coordinates were imported to both measuring projects (in the scanner interface) at the stage preceding field measurements; 3) both measuring stations and targets constituting reference points were located at predefined network points with accuracy of 1mm. Such high accuracy could be maintained by using standardized devices: 1) 6" blue-white Leica target was used to establish the reference. This  target is set on a 1m high geodetic pole and levelled on a geodetic tripod (the accuracy of the positioning of this target type by scanner is specified by the manufacturer at 1mm); the scanner was located exactly above the GCP point by the use of a built-in laser plummet and a set of the scanner mirror precise height measurement (provided by the manufacturer). The rigorous application of these procedures during both measurement campaigns, the individual and merged point clouds and the DTMs generated from them can be compared directly. Therefore, the description refers to the unreduced data.

2) Lines 293-297, Table 2: the table is too cumbersome and difficult to understand. Lines with "Total volume of difference." and "Average total thickness of difference ..." are redundant. The table content is already overloaded.

A: Indeed, the table is long but follows the layout recommended by the authors of DoD and GCD [e.g. Leary RJ, Hensleigh JW, Wheaton JM, & Demeurichy KD. Recommended Geomorphic Change Detection Procedures for Repeat TLS Surveys from Hells Canyon, ID. Ecogeomorphology & Topographic Analysis Lab, Utah State University, Prepared for Idaho Power Company, Logan, UT, 144 pp.]. The proposed layout is the same, but the table contains 4 parts [A-D] because we have included calculations for whole studied area and for each of the separated zones (see Fig. 3). Since other researchers using this method may want to know all the calculated parameters, we have decided to include the table in its unchanged form as an Appendix 1 A-D in the supplementary files.

R#2: Line 305-306: “…the character of the Scottbreen’s terminus surface lowering was polygenetic”. It would be better to be more specific and clear. What exactly is the polygenetic nature of surface lowering? Ice ablation and..?

A: Removed unnecessary sentence rather than adding new content for clarity; "polygenetic" term referred to the processes causing terminus degradation e.g. descending, cutting through supra-glacial channels, etc.

R#2: Lines 321 and 445: does it mean that the thrust (by 1 m up) occurred in 21 days on glacier terminus ?

A: I couldn't find reference in line 445

A: They are landforms of about ~1 m in height, at sites of deposition of sediment particles transported down the glacier. So this value means there was not so much rising of the ice surface along the line parallel to the glacier terminus (the structural crack parallel to the terminus range). The sediments transported down the glacier change direction and are deposited along these lines. On the one hand, we have therefore deposited moraine material along the cracks parallel to the terminus, and on the other hand, moraine material covering the ice which causes slower melting of the glacial ice protected by sediments. This surface melts relatively slower than the surrounding pure ice.

R#2: Line 329 Figure 5: the color scale on Figure 5 is pleasant to look at, but does not help in any way to see the details of the surface change on the maps. Shadowed DEM background also interferes with this.

A: Figure 5 is divided into two according to A and B panels. A colour scale was added to each. The colours have been improved to best match the result presented.

R#2: Line 331: “…major contours every 5 m; minor contours every 0.25 m.”  contour lines are absent or not visible on Figure 5.

A: The contour lines were removed from the figure earlier because they were difficult to interpret. They were replaced by hillshade in the background. Thus, the sentence about the contours was also removed from the caption.

R#2: Line 338: sentence “…a number of new landforms have been mapped as a result of the glacier's front retreat…” is not perfectly accurate. Better to say that a number of new landforms created by glacier were mapped.

A: Improved as suggested by the reviewer.

R#2: Line 389: The possibility that the subsidence in some parts of this zone might be the result of thawing of frozen ground or buried ice is not considered. It is not possible or..?

A: It is assumed that there is no permafrost under a polythermal glacier such as the Scottbreen. In line with the reviewer's comment, only ‘buried ice’ was added.

R#2: The text needs to be edited to make it clearer, more precise, and more specific. For example, phrases like this (lines 353-355): “The lifespan of these 'ephemeral landforms' depends on the adaptation to the new functioning conditions and the polygenesis of the morphodynamic processes”. - can be written simpler, clearer, and shorter. I have no way of pointing out every such place in the text, but I think that unnecessary and  inaccurate words and phrases is a serious flaw.

A: Unclear and unsuitable wording deleted

R#2: Line 413: I do not find in this section the real discussion of numbers presented in Table 2. For example, Table 2 shows for the glacier forfield (D) the total net volume difference as +5596 m3 on total area 87880 m2. It means +6.37 cm per 21 days or +3 mm/day. What is the density of sediments? Is it possible to compare these rates with other observation ?  etc.

A: A section discussing the results of short-term measurements has been added, and it refers to previously published data of similar extent. There was no sampling of sediment, so we cannot answer the second question. Added section:

‘This study shows short-term erosion and deposition distributions for each analysed area. In the clean ice zone, surface lowering is dominant (99%) due to rapid ice melting. In the 3-week period, the average lowering of the glacier terminus surface was recorded to be 0.84 m (0.04 m per day). By contrast, this is much higher than the average (2.2 m per year; 0.13 m per 3-week period; and 0.006 m per day, respectively) which was noted over a 3-year span between 2010 and 2013 [44]. By comparison, a slightly lower rate (0.39 m per 3-week period and 0.02 m per day, respectively) was determined for the retreat of the Sólheimajökull glacier over a period of 14 years [16]. Furthermore, surface lowering also dominates (95%) in the narrow zone of the recently-deglaciated area, which results in an average decrease of 0.54 m (3-week rate) and 0.026 m (daily rate), respectively. It is worthy to note that a slight predomination of surface rising (53%) was only recorded in the glacier’s forefield zone. This slight advantage of deposition equates to an average increase of 0.064 m over the 3-week period (0.004 m per day). In the above-mentioned 3-year span, some much lower average rates had been determined for Scottbreen’s near forefield (0.025 m - annual; 0.001 m – 3-week; and 0.0001 m - daily, respectively), whereas these rates were comparatively 2-times higher for its intramarginal outwash fan (0.059 m; 0.003 m and 0.0002 m, respectively) [44]. However, this zone was observed to have different trends in its various cold regions. Similar average values but of surface lowering (−0.05 m - annual; 0.003 m – 3-week; and 0.0001 m - daily, respectively) were determined for the Midtre Lovénbreenand (NW Svalbard) forefield over a 2-year period, and these were based on comparisons between LiDAR-derived DEMs/DoD. In reference to those values, average surface lowering was even higher  (0.7 m per year; 0.04 m per 3-week period; and 0.002 m per day, respectively) for the moraine downwasting [37].’

R#2: Line 466: where is pole no.2? Is it the same as SC2 or..?

A: corrected, replaced on SC2

R#2: Lines 474-477: 1) When it was another above-average precipitation episode (which occurred at the end of the ablation season)?  - give the dates.

A: Corrected and supplemented

2) Lines 474-477:  When it  was another above-average precipitation episode (which occurred at the end of the ablation season)?  - give the dates.

A: This is the authors' mistake. There was no ‘another above-average’. It was corrected and supplemented.

R#2: Line 526: here is an example of a non-specific verbiage

A: This area is constantly changing, which worsens during rapid and above-average events (e.g. heavy rain, a sharp rise in air temperature, etc.)

Yours sincerely,

Waldemar Kociuba

Author Response File: Author Response.docx

Reviewer 3 Report

Waldemar et al. presented the retreat and patterns of Scottbreen Glacier from high-resolution differential digital elevation models based on terrestrial laser scanning surveys. Overall, this manuscript is good and suitable to publish in Resources. However, the writing need improve greatly before possible publication. Please see detailed comments below.

Major comments:

1. Abstract should be shortened.
2. The English writing of this manuscript need improve.
3. Figures are not clear. Figure 5 is too large. All figures need improve for publication.
4. Table 2 is too long, and should be moved to Supporting Information.
5. The main text is too long, such as Conclusion section, could be shortened and concise.

Specific comments:

1. “. 53,475 m3 ± 1 761 m3 (of the ice disappeared 29 from the glacier snout area (62,250 30 m2).” This is a sentence?

2. “increased recession [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19].” Too many papers are cited in one place. Please just select less than five important ones. Other places are same problems, please revise.
3. “These methods include: satellite radar and photogrammetry measurement [27].” Suggested references here:

Bolch, T., et al., Status and Change of the Cryosphere in the Extended Hindu Kush Himalaya Region, in The Hindu Kush Himalaya Assessment: Mountains, Climate Change, Sustainability and People, P. Wester, et al., Editors. 2019, Springer International Publishing: Cham. p. 209-255.

Zhang, G., et al., Glacial lake evolution and glacier-lake interactions in the Poiqu River basin, central Himalaya, 1964−2017. Journal of Glaciology, 2019. 65(251): p. 347-365.

4. “100 m to 160 m” to “100 to 160 m” Others are similar problems.

Author Response

Response to the suggestions and comments of the Reviewer #3,

We are grateful to the Reviewer for their tremendously helpful comments regarding the proposed version of the article resources-992800 entitled ‘A Short-time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (case study: Scottbreen Glacier, SW Svalbard)'. We attempted to consider all of the Reviewers’ and Editors’ comments and remarks in order to adjust the text to the requirements of Resources Journal.

General changes to the text

1. The title was reedited and changed; the new title is ‘A Short-time Repeat TLS Survey to Estimate Rates of Glacier Retreat and Patterns of Forefield Development (case study: Scottbreen, SW Svalbard)’
2. All figures was reedited according to Reviewers’ comment
3. The entire Table 2 has been moved to ‘Supplementary files’ as ‘Appendix 1’.
4. References were verified and supplemented
5. The text has been redrafted and shortened where possible. The meteorological description has been reworded to remove unnecessary information and moved to ‘Results’ chapter. The section has been reduced to include information that is most relevant in explaining the phenomena described in the glacier foreground during the period under review. A selection of better matched terms was made, in line with and according to the Reviewer’s suggestions. The entire text of the manuscript was corrected and improved. English language content was carefully proofread following the Reviewers’ suggestions by a native English speaker, Luke Boczkowski.

All comments and suggestions contained in the review have been taken into account.

Response to general comments and suggestions for Authors (Reviewer #1):

R#3: Waldemar et al. presented the retreat and patterns of Scottbreen Glacier from high-resolution differential digital elevation models based on terrestrial laser scanning surveys. Overall, this manuscript is good and suitable to publish in Resources. However, the writing need improve greatly before possible publication. Please see detailed comments below.

A: Thank you for all the useful feedback. All comments and suggestions have been included in the revised version of the manuscript.

R#3: Abstract should be shortened.

A: The repetitions in the abstract were reduced. This section has been a little shortened.

R#3: The English writing of this manuscript needs to be improved.

A: Proofreading by an English native speaker has been performed again.

R#3: Figures are not clear. Figure 5 is too large. All figures need improvements prior to publication.

A: All figures have been re-edited and corrected. Figures 1 and 5 was split into separate ones.

R#3: Table 2 is too long, and should be moved to Supporting Information.

A: Table 2 has been moved to the ‘supplemental files (Appendix 1 A-D)’

R#3: The main text is too long, such as Conclusion section, could be shortened and concise.

A: Substantial parts of the text have been reworded and shortened

Response to specific comments:

R#3: “. 53,475 m3 ± 1 761 m3 (of the ice disappeared 29 from the glacier snout area (62,250 30 m2).” This is a sentence?

A: Duplicate text was deleted

R#3: “increased recession [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19].” Too many papers are cited in one place. Please just select less than five important ones. Other places are same problems, please revise.

A: Verified list of references – kept five references to the most relevant and best suited papers

R#3: These methods include: satellite radar and photogrammetry measurement [27] ].”

Suggested references here:

Bolch, T., et al., Status and Change of the Cryosphere in the Extended Hindu Kush Himalaya Region, in The Hindu Kush Himalaya Assessment: Mountains, Climate Change, Sustainability and People, P. Wester, et al., Editors. 2019, Springer International Publishing: Cham. p. 209-255.

Zhang, G., et al., Glacial lake evolution and glacier-lake interactions in the Poiqu River basin, central Himalaya, 1964−2017. Journal of Glaciology, 2019. 65(251): p. 347-365.

A: Added proposed references

R#3: “100 m to 160 m” to “100 to 160 m” Others are similar problems.

A: This sentence was reworded on ‘The constantly tilted glacier zone has an average slope of 10° (Fig. 1C) and is deeply cut through by subglacial outflow channels (winding, meandering development patterns), whose length ranges from 100 m to 160 m in length).’

Yours sincerely,

Waldemar Kociuba

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors constructively considered all my comments and suggestions and gave a clear response in their answers and specific changes to the manuscript. I confirm that the revised version 2.0 is now ready for publication in the journal but should be carefully checked again for typos. At least I found one misprint in line 89: instead of "glacieTable1rs" should be "glaciers".

Reviewer 3 Report

The authors have addressed all the comments. I have no more suggestons, and agree with the publication of this manuscript in present form.