Dear Mr. Mewes and co-authors,

this is a very well written paper on the resolution capacity of ERT and SRT as components of a 4-phase model using synthetic and field data sets of mountain permafrost terrain. This paper significantly adds to the existing body of knowledge on 4-phase model validity and interpretability.

The reviewer comments have been carefully implemented in the text and the paper is well structured, concise and to the point.

I have re-checked the paper (not from a reviewer but) from a editors point of view and I attach a commented pdf with two handful of minor technical suggestions and I have listed a few minor necessary corrections below.

Otherwise a very nice and significant paper which should be published after these minor technical corrections.

All the best, Michael Krautblatter

P4L4: RMS errors are also a systemic measure of the spatial variability of apparent resistivities and have e.g. been used to characterise fracture density in bedrock; so they might not only refer to contact resistance issues but also reflect strong resistivity gradients in the measured objects. If this is what you want to say you should make this statement more clear.
P4L8 could you shortly state how the locations were arranged in and outside the receiver array.
P5L11 At UK Universities, all specifying numbers. Step 1, Layer 2, Figure 3 & Table 4 relate to a capital first letter at the denominated item. Consider whether you want to apply it here, especially as you use it for figures, e.g. Figure 4.
P6L32 Omit brackets and their hierarchy – it is difficult to read.
P11L14: “Increasing water content in an unfrozen blocky layer would lead to a resistivity decrease (water having a lower electrical resistivity than air, rock or ice, cf. Tables 1 and 2) and a P-wave velocity increase, as the P-wave velocity of water 15 is higher than that of air (1500 m/s versus 330 m/s, cf. Table 2).” – I think you don’t have to repeat the information given in brackets here since this is already introduced beforehand.
P12L1: As a heading, I would write it without abbreviation as "4-phase model"
P13L20: “Largest errors are introduced by horizontally saturated layers (such as in SYN2) which are overestimated in thickness due to 20 inversion artefacts, which in consequence lead to an erroneous decrease in ice content. This results in false ice loss detection in this scenario.” – simplify see comments in the pdf
Fig. 4 increase size of numbers
Fig 12: you display percentage rather than fractions - please change the caption.