Dear X. Wang et al,
Thank you for your substantial revision of your paper and for adressing the comments/concerns oft he two reviewers. As the revisions were rather substantial i will send the paper out for review again. However, although the authors have also adressed most of editing and writing (English) issues highligheted by the authors, the revised parts and new text passages clearly suffer again from such editing/wrting issues (singular/plural, missing articles, awkward/confusing formulations etc...). I have listed some below (the most obvious) but this list is not exhaustive. So, before I can send the paper out to review again, i ask you to carefully check the whole text again for editing issues and writing etc as we should not expect that the reviewers should do this editing job. I am sure the reviewers will very much appreciate your effort on this. Not that the list below is probably far from complete and there may be more issues that I did not spot when reading through quickly. So although the system may say ‘major revision before reconsideration’ it actually is rather ‘minor’ revisions (as easy to do) before sending it to re-review.

Thank you and best regards
Andreas Vieli
The editor


Some obvious editing/writing issues:

Line 129/130: ‘…for each of the datasets from Novemeber…’

Line 133: should be in plural: ‘clouds’

Line 137: add ‘the’: ‘…correction from the TPX07.1…’

Line 139: ‘under WGS-84 ellipsoid’ seems awkward, maybe ‘…using the WGS-84 ellipsoid …’ or ‘…with the WGS-84 ellipsoid …’ would be better

Line 148: i think the word ‘even’ is here rather awkward and is not needed here.

Line 151: I can not follow ‘…MIT almost repeatedly along the same track…’. Rephrase clearer.

Line 173 and elsewhere: please remove the inverted commas around all the variables in the text (e.g. ‘x’), writing them as italics is enough.

Line 173 to 178: whenever it say something like…‘var1’ and ‘var2’ is… I think you should use the plural for the verb: …‘var1’ and ‘var2’ are… and then the noun later should also be in plural (for example: t1 and t2 are the start and end times.

Line 183: replace ‘kriging’ by ‘it’

Line 203: replace ‘…will be soon introduced…’ by ‘…is introduced…’

Line 218: change to ‘…convenient (…) and is defined…’

Line 226: delete the second ‘layer’ (‘…of the firn layer on top of an …’)

Line 234: simplify to ‘It is critical to target and use icebergs that fulfil these requirements….’

Line 249-250: remove: in terms of estimating ….itself.

Line 295-296: move the ‘and’ to after ‘Delta_E_krig’

Line 308: ‘is relatively correct’??? I do not understand this, do you mean ‘reasonably accurate’?

Line 320/321: ‘the interpolated freeboard’ rather than ‘the freeboard interpolation’? AND ‘in average’

Line 349/350: ‘…and outlines of the MIT … are shown…’

Line 364: add a comma after ‘Also’. This sentence is as a whole a bit awkward.

Line 374: ‘as time passed on’ (rather than ‘with passing time’)

Line 390: awkward formulation: maybe write ‘…needed to climb more 140m to pass it…’ or ‘ …needed to climb the 140m obstacle to cross it’.

Line 408: I think this should be Fig. 8 (not Fig 7)

Line 442: the ‘70 years’ are in a random place in this sentence, maybe write: ‘Additionally, the 70 year cycles of MIT…. well which make …’

Line 450: ‘…are discussed in more depth/detail’

Line 456: where does the number -3.35 m come from?

Line 498-499: awkward formulation, maybe say: ‘However, other time dependent modelling results from the Mertz region were close to …..’ and delete: ‘Our result is smaller’.

Line 475: somewhat awkward formulation: ‘worked only several times a year..’ change.

Line 476: add a ‘the’ before ‘elevation’.

Line 481-482: awkward: maybe say: ‘Since the larger freeboard measured in 2006 indicates ….’

Line 484: ‘…reason to select the measurement…’

Line 487: ‘…is critical to the final success…’

Line 489: ‘…along the margin…’

Line 492: ‘…front, for both the east and west flanks, …

Line 495: I do not see a white polygon in fig 6, do you mean the light grey dash-dotted line with label 20000125? Clarify and maybe change labels in fig 6 to the years (e.g. 2000).

Line 499-450: awkward formulation: ‘…but only the poorest accuracy …’, rephrase

Line 500-502: awkward sentence, rephrase (‘…it is not possible to conduct further work on evaluation of the seafloor bathymetry ……is difficult to assess’.

Line 504-507: I do not understand these sentences.

Line 516: ‘gradual’ (not gradually)

Line 544: ‘…is a/the dominant factor….’


Figure 5: caption of figure: please carefully check and rewrite caption, for example (a) does not show ‘freeboard’ but profile locations …

Caption Fig 7Line 774: ‘The grounding sections of the MIT boundary in …’

Supplementary figure 1: please check and rewrite caption of this figure very carefully:
Line 3: ‘in THE red rectangle…’?
Line 4: use date rather than 50th day
Line 5: ‘Blue polylines show the seafloor contours…’
Line 6 onwards: does this all have to go into the bracket? These are several sentences!!!
Line 7: ‘However, for being able to use the Figures…..’???
Line 8: ‘geo-registered’
Line 10: ‘…with THE thick gray line…’
Line 11: successful (not successfully)

Editor decision after reviews of revised revision.

Dear X. Wang et al,
The revised version of the manuscript was sent to 2 reviewers again (comments further below), and although they both indicated that the revised version has improved to some degree (compared to the original submission) they both stated that the general writing and English language clearly need further improvement, a point that I also made to you after the first revised version of the manuscript. I then already asked you to carefully edit and correct the whole document again, and not just the few points that I spotted. It is really not the job of the reviewers to correct the manuscript for English language grammatical errors, irregular punctuation, and awkward phrasing, but the author’s. Both reviewers seemed rather disappointed regarding this aspect of the revised version.
Reviewer 2 had beside the English languages issues some rather minor further points to address (see list of reviewer 2), of which some concern the definitions/explanation (e.g. sea floor elevation, E_sf) in the methods.
Reviewer 1 was less positive and had besides the major language issues some rather substantial remaining issues concerning the methods and presentation (see major comments by reviewer 1) and on this basis recommended to reject this paper. As an editor I agree in principle with some of the more substantial points made by reviewer 1 but I think they are relatively easy to be addressed by the authors and do not fully justify a rejection.

So, I suggest to the authors to very carefully address the
(i) To very carefully address ALL the minor comments and points listed by the reviewers 1 and 2

(ii) Re-check and correct the ENTIRE publication again VERY CAREFULLY for English language, grammatical errors, awkward phrasing and small editing issues. I advise you to get the whole document checked again at the end by a native English speaker.

(ii) To address the following more substantial points (a-d) by reviewer 1:

(a) Reviewer 1 is concerned about the calculation of E_dif below the substantive areas of MIT where no bathymetric data are available (only extra/interpolated). While such an E_diff can (theoretically) be calculated using the interpolated bathymetric data, I agree with the reviewer that it has not that much meaning other than based on the interpolated data (and other indicators) it is likely that MIT is floating there. There is a supplementary figure now showing where there is actually bathymetric data which helps regarding this aspect, but I would try to make this point a bit clearer in the main paper. There are a variety of ways to do this, here some suggestions:

-Provide the justification and all the available evidence for believing ‘that the tongue is floating’ rather than to carry out and show the entire calculation for E_dif based on extrapolated sea-floor heights.
-or clearly mark in fig 3 and in fig 6 (maybe with black hatching or similar) the areas where there is no bathymetric data available (or is just extrapolated).
-or show supplementary figure 1a) as Figure 3b).
Whatever option is taken, in the text it should be made clearer that the E_dif

(b) regarding the detection of grounding from E_dif: I agree with reviewer 2 that the statement on line 340/341 of ‘…E_def less than 23 m corresponds to a very robust grounding event...’ seems not quite right and also not consistent with the figures and interpretation in section 5 (line 353: E_dif less than 23m interpreted as ‚almost grounded’). Maybe there is just a minus sign missing in front of 23m on line 340, I think it should say: below -23m it seems very strongly grounded, between -23m and 23m slightly grounded and above 23m unlikely to be grounded. Please check this carefully and adjust accordingly in whole document.

(c) Address the more structural issues (methodological explanations to the methods, discussion points to discussion (see detailed comments by reviewer 2).

(d) Clarify the point on applying the firn-air content calculation on heavily grounded ice bergs. I assume although you use ‘heavily’ grounded they are still very close to floatation but hardly move and hence flotation still is applicable.

Thank you and best regards
Andreas Vieli
The editor

18 May 2016



Comments Reviewer 1:
This is my second review of this paper. I am somewhat disappointed with the revisions, in that one of the key points in my, and the other reviewer’s, review was that the paper needed careful editing by the authors before it would be publishable. It appears that some of the edits suggested by the reviewers and the editor are included in this version, but that the authors have not found the grammatical errors, irregular punctuation, and awkward phrasing that were not specifically identified during the first review process. These remain in the present manuscript and it is the authors’ responsibility to correct them.

The paper also remains somewhat disorganized. The discussion section contains material that belongs in the methods section, and the results section contains material that belongs in the discussion section. I have made some notes to this effect, but the authors should revise the paper carefully to make some that each section contains only the appropriate material.

For the scientific content of the paper, I am concerned to see that the authors are still presenting their calculation of E_dif under the MIT in areas where there are no measurements of bathymetry. There is a small area near the northwest edge of the tongue where the MIT has overrun some measured bathymetry, and in these areas it is appropriate to calculate E_dif, but for the rest of the tongue, it seems cleaner to provide a justification for believing that the tongue is floating than to carry out the calculation based on extrapolated sea-floor heights.

The firn-air content calculation does not seem very useful. To calculate the firn air, the authors must use a point where the bathymetry is known, so that the ice bergs are grounding. But if the bergs are grounded, the hydrostatic approximation does not apply.

Last, the authors seem to have the detection limits for their grounding detection wrong. E_dif is equal to the inferred elevation of the ice bottom minus the sea floor. Suppose sea floor is known to be at -500 m, and the bottom of the ice berg is inferred to be at -524 m, give or take 23 m. Then E_diff=-24, with a one-sigma range between -47 and -1 meters. Likewise, if the bottom of the ice berg is inferred to be at -478 m, give or take 23 m, then E_diff =+22, with a 1-sigma range between -1 and 45 meters. The first case represents robust grounding, the second case In section 6, the authors say :
“E_diff less than 23 m corresponds to a very robust grounding event”.
A robust grounding event should be one where the one-sigma range is entirely below zero ( my first case ) while a plausible, but not robust, grounding even is one where the one-sigma range includes zero, but also includes positive values (my second case). If E_diff is greater than 23 m, then at one sigma you can be confident that there is no grounding.





87, Delete sentence beginning “With billions…” The other data types are not relevant here.

132- This seems wrong. Clouds cannot cause ICESAT saturation.

136: You subtract off TPX07.1, but do you reapply it in the freeboard calculation? The freeboard is the ice surface height minus the sea-surface height, and if you don’t use a tide model, the tidal elevation causes an error.

138-139: Not sure what this means. Please explain or delete.
158-166: How are height gradients taken into account in this calculation? For a sloping surface, relocating the footprints by the ice velocity will introduce a spurious elevation change signal.

170: These equations need to be placed immediately after their introductory sentence. I suggest deleting the reference at 165 to these equations and adding one sentence such as “The corrected positions of the footprints are:” at 170.

179: don’t need to discuss interpolation techniques not used here.

186: Put equation 4 here, not eight lines below.

253-56: How are the PIG icebergs relevant here? I suggest deleting the reference.

266-68: If the iceberg is grounded, then the bed is supporting some part of its weight. This means that it is not in hydrostatic equilibrium: rho_w D < rho_i (H_f +D –FAC). This seems to introduce a potentially large error into your calculation of FAC.

265-270: Are you using all the ice bergs, or only the 2006 measurements? If the latter, is this a least-squares calculation, or just a simple solution?


331: 50 times 0.00024 is 0.012. This is not a realistic estimate of the surface slope due to rugged, crevassed ice-tongue surfaces.

384-395: this material belongs in the ‘Discussion’ section.


Section 6.1:
Why does it make sense to talk about the area rate rather than the longitudinal flow rate? The mechanism proposed for interaction between MIT and the Mertz bank is that the MIS should break after it hits the bank. The time for the MIT to reach the bank after it calves is then distance between the end of the MIT and the bank divided by the speed of the end of the tongue. Casting this in terms of area seems to make the calculation more confusing, and is not clearly more accurate.

Section 6.2: Most of this material belongs in the ‘methods’ section, where you should explain the limitations of, and the rationale for, your methods. It also sounds here like you are solving for the FAC using only the 2006 ice-berg heights, while before it sounded like you were including all the data in a least-squares calculation.

484: The discussion of the accuracy of the bathymetry belongs in the data section.

497: Talking about the accuracy of the seafloor DEM under MIT makes little sense, because there are no measurements there, and the values provided are extrapolated/interpolated from measurement locations that are often far away. The arguments (503 - 517) that the bulk of MIS is floating are a better approach than making unfounded assumptions about the height of the bed where no data are available.


Figure 3: There are too many colors here. The bathymetry needs to be in a color scale that does not overlap the colors chosen for the outlines. Consider grayscale.

Figure 6: Indicate clearly the areas in which the seafloor elevations are constrained by data. Do not show E_diff where they are not.

Figure 9: this figure is out of order, and is probably unnecessary.


*******
Comments Reviewer 2:
The incorporated revisions have considerably improved the manuscript. A few minor revisions are listed below.

line 29: Replace “The calving of MIT can be cyclical because…” with “In the calving induced by iceberg collisions, our observations suggest that calving of the MIT is a cyclical process controlled by the presence…”
line 40: Change “… Mertz polynya, and sea-ice production and dense, shelf-water formation” to “…Mertz polynya, sea ice production, and dense shelf water formation…”
line 47: Change “how severe the grounding was” to something like “the extent of grounding” or possibly even “the severity of grounding”
line 60-61: This is a somewhat odd sentence “Grounding as a potential factor can affect the stability of an ice tongue…”. I would suggest that you revise and rephrase to indicate how grounding can affect ice tongue stability, not just state that it can influence stability.
line 77: “launched” not “lunched”
line 130: Change to “The first step involves data processing…”
lines 134-135: “… are corrected following the procedures in Wang et al. (2012, 2013).”
line 137: If I’m interpreting this correctly, change to “… to obtain estimates of the instantaneous sea surface height.” You talk about extracting sea surface elevations in the next paragraph, however, so I’m not sure that’s what you mean here.
line 139: How are the data prepared for use?
line 150: What do you mean by “almost repeatedly”?
line 156: “For example, consider ICESat data from…”
line 158: “… distance between track T165 and T31 is ~7.5 km without accounting for ice advection between observation dates.”
line 170: Remove “a little”
line 184: Replace “because of known ice tongue outlines from Landsat images” to “when the ice tongue outline can be delineated from Landsat images”
line 186: “… assuming hydrostatic equilibrium and using the lowest sea-surface height (further discussed in section 6.2.2), which is extracted from ICESat/GLAS data…”
line 201: Remove “at”
line 209: You don’t need to define Edif here since you just defined it before the equation but you need to define Esf (which I assume is the sea floor elevation).
line 213-214: The author’s name is “van den Broeke”
line 228: “that will influence the density of the ice tongue” rather than “that makes ice mass calculation complicated”
line 311: “compared with interpolated freeboard estimates”
line 325: Add a reference for the inter-campaign uncertainty in ICESat data
line 372: I recommend changing “was grounded more significantly” to “became more firmly grounded” because you aren’t performing any statistical tests.
lines 399-400: Remove one of the “over this period”
line 411: End line 410 with a period after the reference then start a new sentence explaining that, based on your observations, you think only one large calving event occurred. (“Based on the interactions between the Mertz ice tongue and Mertz Bank suggested by our observations and described below, it is likely that only one large calving event occurred between 1912-29156.”)
line 425: “Because of the continuous advection of ice from upstream and the fixed location of the shallow Mertz Bank, the calving is…”
line 434: Of “the” Mertz polynya.
line 439-441: Why would a shorter ice tongue lead to a reduction in katabatic winds (which are driven by air temperature and pressure gradients over steep grounded ice) and polynya size? Elaborate.
line 443: “Mertz wellwhich”?
lines 512-514: I’m not sure I follow this. Why does the absence of shadowing (of ice, the ocean, ???) indicate flotation?
Figure 3: Change the color and/or relative position of the dashed-dotted line so that it is easier to discern.

Dear authors,
The re-revised version addressed a lot of the issues listed by the reviewers including the more substantial ones of the missing bathymetric data under the main tongue, the structural issues and the corrections in the explanations for E_diff.
Unfortunately, there are still a lot of editing issues and awkward wording, a lot of them are in new or rewritten text parts and further the restructuring introduced some additional issues in explaining the methods. So despite having addressed most raised points by the reviewers the language, writing and wording remains unsatisfactory if not even sloppy, and gives the impression that the authors did not take the very clear instruction of the editor of ‘re-checking and correcting the ENTIRE publication for English language, grammatical errors, awkward phrasing and small editing issue’ very seriously.
Again, it is not the editors or the reviewer’s job to do this. I understand that English is not the first author’s mother tongue but some of the co-authors or another native English speaker could maybe be asked for help.
I spent a lot of time going through this document now, and listed whatever I saw or struggled with in detail below, but I may likely not have spotted all and it is probably still not perfect. I give the authors here another chance to correct, tidy and check the whole document, but I asked them to very carefully and thoroughly do these revisions.

Specific comments/issues to be addressed:

To clarify where bathymetric data exists, in Fig. 3 the ship tracks with bathymetric data are now shown as (b) and (c) (from supplement), however, the scale is very different compared to (a).
For easing the readability of theses figures and clarification, I would suggest to show these ship tracks for exactly the same frame/area as in (a) (all the tracks outside are really not relevant).

p. 2 Line 14: I would remove ‘some’ here.

p. 2, line 29/30: ‘In the calving induced by iceberg collision’ is an awkward formulation, the iceberg collision has nothing to do with the cyclic calving, so I would say: ‘ Our observation suggest that the calving of the MIT is a cyclical…’.

p. 2 line 32/33: Make clear that you refer to work from orther studies here, e.g. ‘…This calving cycle also explains the cyclic variations in sea-surface conditions around the Mertz detected by earlier studies.’

p. 3 line 55/56: awkward wording ‘…allows the causes ….gradually come into focus…’ . I would rather say: ‘…allows to investigate the mechanisms of ice tongue instability and calving .’

p. 4 line 62/63: awkward wording: maybe rephrase it to ‘Grounding has been suggested as a potential mechanism to affect the stability of MIT by delaying calving ( Massom…) .

p. 4 line 65-70: somewhere here a reference to Fig 3 would be useful.

p. 5 line 95: something wrong here in this sentence, ‘fundamental’ would be correct.

p. 5 line 99: change to ‘…(DEM) for which the spatial coverage can be found in Figures 3b and 3c.’

p. 6 line 104: delete ‘at least’ as unclear how this is meant.

p. 6 line 105: I do not understand this explanation, what do you mean by the bathymetric gap and how does identifying it help here? does the 2000 data extend furthest into the ice tongue? But this only really helps at the tip of the MIT (where it later grounds). Maybe delete this sentence.

p. 6 6 line 107. The data in west and east provides the outer boundaries (tie-points) for the interpolation but not really controls for seafloor depth underneath tongue!!!

p. 6. Line 109: awkward wording, maybe say: ‘…the MIT varies depending on distance to margin.’

p. 7 line 129 /130: awkward wording, maybe change to: ‘ The methods we designed for grounding detection of the MIT using ICESat/GLAS data are introduced here.’

p. 7 line 142: awkward wording, maybe change to: ‘ ‘…or high reflection from natural surfaces’.

P. 7 line 142: add a comma after ‘Thus’

p. 7 line 147 ‘…for the instantaneous …’ )not ‘…of the…’

p. 7 148/149: I do not understand this sentence: do you mean is ‘available’ for subsequent use?

p. 8 line 167: should it not be ‘from March 22’ and ‘from November 1’?

p. 9 line 179/180/181: awkward wording, I would simplify this to:
‘…where x and y are the horizontal positions directly from ICESat measurements, and X and Y the horizontal positions after relocation respectively. vx and vy are the horizontal components of the ice velocities.

P. 9. Line 193: ‘…for November…’ (not ‘on November’)

p. 10 line 197: I would introduce the ‘lowest sea surface height symbol E_sea_level already here ((and not on line 219) and slightly rephrase and shorten this: ‘…and using the lowest sea surface height (E_sea_level) as reference for the sea surface elevation:’ and then eqn (4)

p. 10 line 200-202: there are a lot of ‘the’ missing here: ‘…where D is the ice draft…from the sea surface to the bottom of the ice; Hf is the freeboard, i.e. the vertical distance from the surface to the top of the snow; …are the densities…’

p. 10 line 203: ‘…FAC is the firn air content which corresponds to the decrease …’

p. 10 lines 206-209: should be clearer, rephrase to:
‘The sea surface is taken as the lowest sea surface height (E_sealevel) and is derived from the minimum of all sea surface heights from the different ICESat/GLAS tracks between 2003 and 2009 and amounts in our case to -3.35m’.

p. 10 line 213: add a ‘the’ in front of ‘ice bottom’.

p. 10 line 215/216: rephrase to: ‘ The elevation of the underside (bottom) of the tongue E_ice_bottom is calculated from:’ then eqn (5)

p 11, lines 219 and 220 can then be removed (as repetition.

p. 11 line238: ‘…are available..’ (not ‘…is available…’) as it refers to measurements.

p. 246-249: this applies for any iceberg (not just for those calving from MIT) and awkward wording , I would change/simplify this to:
‘…from surrounding icebergs that are slightly grounded under the assumption of hydrostatic equilibrium and known ice draft and freeboard. It is, however, critical to target and use icebergs that fulfil the condition of slight grounding.’

p. 12 line 258-260: maybe rephrase to: ‘ However, slowly drifting or nearly stationary icebergs in open water are good indicators for slight grounding and therefore be used to infer FAC.’

p. 13 line 266: I would rather use ‘investigated’ than ‘identified’ as you track/observe/study their position.

p. 13 line 269/270: awkward wording, maybe rephrase to:
‘Fig. 4a shows that icebergs …..were almost stagnant and only slightly changed their positions and orientation over two months (…).’

p. 13 line 278: replace ‘In this study,’ by ‘Therefore,’ and ‘employed’ by ‘used’

p. 13 line 282: ‘where k refers to the icebergs ‘A’ or ‘C’,…’

p. 14 line 298: rephrase ‘For Mertz we obtain a FAC of 4.87….. Other studies, using a time variable approach, modelled FAC values between 5 and 10 m (…) and in the absence of in-situ measurements our estimates seem consistent, but there are some shortcoming which should be .’ Delete next two sentences (line 301-303.

p. 15 line 315: rephrase: ‘…may not refer to the same…’

p. 15 line 319: rephrase to ‘ …or observing a different portion of the iceberg…’

p. 15 line 322: ‘…a similar…’ (not ‘the similar’)

p. 15 line 323: I would rather say ‘…for the inversion’ (than ‘to invert’)

p. 16 line 337: I would leave away the ‘Usually’

p. 16 line 338/339: delete the ‘law’ and say just ‘…by:’ instead of ( ‘by Eq. (9):’

p. 17 line 359: ‘interpolated freeboard’ (not ‘freeboards’)

p. 18 line 377: Rephrase to: ‘Using Eq. (9) and kriging interpolation….’

p. 18 line 381: change to ‘slight grounding’ or ‘slightly grounded’

p. p. 18: line 387/388: it is not clear to me what is really done with this buffer region and more important, how is E_diff calculated in this buffer region (where no surface data is available)? Clarify.

p. 18 line 394: ‘as illustrated in Table 2 and Fig 6…’

p. 18 line 395: ‘was less than -23 m’ (not ‘were less…’)

p. 18 line 396: replace ‘From this point of view, we conclude that…’ by ‘This suggests that …’

p. 19 line 400: ‘…it would have been difficult…’ (rather than ‘it would be difficult’

p. 19 line 403: ‘slight grounding’ (or ‘slightly grounded’)

p. 19 line 405: again, ‘strong grounding’ (or ‘strongly grounded’)

p. 19 line 412: maybe ‘tip’ is better than ‘flank’

p. 19 line 415: ‘For the grounded part (rather than ‘grounding’)

p. 19 line 418: ‘…lower right (northwest) section of the MIT…’

p. 20 line 430/431: I do not understand how a least square method is used to derive rate of area change, maybe the authors mean to derive the average trend of area change rate. Clarify.

p. 20 line 434: ‘surface behavior’ is not the right term here, do you mean ‘surface dynamics of the ice tongue’?.

p. 21 line 445: ‘…would eventually have calved because of the effect of the shallow….’

p. 21 line 450: ‘…without considering an accidental such as the collision…’

p. 21 line 463: ‘and the MIT calving cycle’ and delete ‘, our explanation is’

p. 21 line 465-470: the wording of these new sentences is awkward, maybe change to:
‘Variations in length of the MIT will prevent sea ice drifting from the east side to a variable degree. A long … because sea ice from the east side can not drift to the west side. The sea ice produced on the West side is blown seaward by the katabatic wind and thereby maintains a polynya and stable sea ice production. The sudden shortening of the MIT after a calving event therefore reduces ….’

p. 22 line 480/490: rephrase to: ‘Additionally, the ice tongue continued to advance out into the ocean, where the bathymetry observation density is good.’

p. 22 line 488: rephrase to: ‘…since late 2002 is well supported by observations and which we take as evidence to infer the …’

p. 23 line 495: ‘strong’ (not ‘strongly’)

p. 23 line 498: ‘…as suggested by Massom…’ (instead of ‘pointed out’)

p. 23 line 498/499: ‘...bathymetric data in the Mertz region…’

p. 23 line 503: ‘…around the Mertz…’

p. 23 line 504: ‘…understanding the MIT…’

p. 23 line 506: ‘… and is performing well.’ (instead of ‘is verified working well’.

p. 23 line 509: maybe ‘dynamic behavior’ is better than ‘surface behavior’.

p. 23 line 514: ‘From these…’

p. 23 line 518: ‘… increasingly diverted by the obstructing seafloor shoal…’

p. 23 line 524: ‘… similar period for variations in sea surface conditions using…’seafloor sediment data. Thus, the shoaling on the seafloor combined with the rate of advance of the MIT determines the 70-year repeat cycle.’

Fig. 3 caption: line 685: shorten to: ‘… MIT from 2002 to 2008 marked with the colored polygons for different years.
It would be very useful to know from which years these bathymetric data in (b) and in (c) are.

Caption figure 6: please make a note here that no bathymetric data under most of ice tongue (for locations of bathymetric data see Fig 3b and c).

Table 1: two entries for C and second last column, make sure the minus sign is on same line as number. Similar, for Row B and last column.

Editor Andreas Vieli, 20 June 2016

Editors decision,

Dear authors,
The 2nd re-revised version of the paper addresses carefully and well the editing-issues raised by the editor and clearly improved the quality and english language of the publication to an acceptable level. There are very few technical editing issues remaining which are listed below and when addressed the paper can be seen as accepted for publication in TC. I thank the authors for there latest effort in improving the paper.
Specific technical and very minor issues to be addressed:

p. 9, line 184: I think there should be a ‘the’ in front of ‘freeboard map’.

p. 21 line 466: ‘…inside THE dash-dotted…’

p. 31 line 657: I think thie ‘the ‘ in front of East Antarctica should be removed.

p. 36 line 689: awkward formulation ‘… can be clear…’. I would rather say ‘… can be read’ or ‘ …over it which illustrates the density of the bathymetry measurements.’

p. 38 line 712/713: ‘…indicates the 7 km x 7km region used to investigate the accuracy of the kriging interpolation method.’

p. 41 line 743: remove ‘that’ after ‘…same legend as…’

p. 44 765/766: awkward wording, maybe change last subsentence to: ‘…and only includes those outside the 2000 Mertz boundary with an elevation difference less than 46 m.’ (Is this what you mean here?).

Andreas Vieli 26th July 2016