the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 17 Jul 2026
A comprehensive TLS-based framework for cave ice monitoring under adverse surface conditions: application at Scărișoara Ice Cave
Abstract. Rapid degradation of cryospheric components requires reliable quantification of volumetric change to understand the leading processes and mechanisms behind the loss of ice. However, such monitoring in cave systems, a particularly complex morphological and climatic environment, remains methodologically challenging due to irregular geometry, limited accessibility, and increasingly dynamic ice-surface conditions. This study presents a comprehensive terrestrial laser scanning (TLS) data-processing framework from noise assessment, surface reconstruction, 3D volumetric change computation and error propagation as a transferable methodology for reliable monitoring of cave ice change even under suboptimal data acquisition conditions. The framework is demonstrated at Scărișoara Ice Cave (Romania) using three annual campaigns acquired with pulse-based and phase-shift scanners under conditions ranging from optimal dry and frozen surfaces to widespread meltwater presence. Scanner-specific noise assessment on different ice surface types reveals pronounced range, intensity and incidence angle dependent errors, demanding an efficient filtering strategy that reduces point cloud dispersion. A hybrid Poisson–MeshFix reconstruction strategy effectively fills meltwater-induced data gaps, reducing modelling error by up to five times. Multiresolution modelling tests show that 5 cm resolution provides an optimal balance between volumetric precision and computational efficiency with errors under 1 % compared to finer resolution models. Comparison of conventionally applied 2.5D change detection and 3D approach reveals ~20 % volumetric discrepancy, confirming that full 3D analysis is essential in such geometrically complex settings. The results reveal a cumulative ice loss of 1521 ± 65 m³ over three years, with heterogeneous spatial patterns controlled by cave morphology and drip-water distribution. Our data clearly shows that omitting any of the evaluated processing steps would greatly bias the volume estimates.
- Preprint
(3369 KB) - Metadata XML
- BibTeX
- EndNote
Status: open (until 28 Aug 2026)
- RC1: 'Comment on egusphere-2026-3512', Anonymous Referee #1, 04 Aug 2026 reply
-
RC2: 'Comment on egusphere-2026-3512', Anonymous Referee #2, 09 Aug 2026
reply
The manuscript ‘A comprehensive TLS-based framework for cave ice monitoring under adverse surface conditions: application at Scărișoara Ice Cave’ by Šupinský et al. presents a detailed multi-year LiDAR survey of the Scărișoara Ice Cave with a careful assessment of the uncertainties of various methods to derive the point clouds and volumes. I found this work to be very interesting and informative, with some key take-home messages for the survey of ice caves. This is a relevant and very complete study that will make a nice contribution to The Cryosphere.
General comments
Level of details: The level of detail is impressive, to a point that I find it sometimes a bit too much as it impacts on the readability of the whole work. Particularly the results and some of the attached tables and figures would benefit to be streamlined to highlight the main observations, with the rest being shifted to Supplementary Material for the readers who want to delve into the technical aspects.
Co-registration evaluation: Upon reading the manuscript, I am not entirely sure how was the co-registration evaluated and the corresponding uncertainties quantified? I was wondering if just using the ceiling for co-registration may lead to some systematic biases? I think it would also be useful to explain how the scan positions are obtained as well as more specifically the functionalities of the total station and how they are used for this work.
Line-by-line comments
L2, 15: Several different adjectives are used to characterize the acquisition, such as ‘adverse’ or ‘suboptimal’, which makes things vague as we don’t know what these refer to.
L24, 567: This sounds like a lot but is difficult to interpret as such. Would be worth adding what it represents relative to the total cave volume, and to the average thinning rate.
L33: It would be worth defining what an ‘ice cave’ is here. I tend to think of ice caves as cavities that form at the glacier base, which obviously is not the case here. Also note that some small glaciers also have accumulation and ablation occurring at the same place - Mott, R., Wolf, A., Kehl, M., Kunstmann, H., Warscher, M., and Grünewald, T.: Avalanches and micrometeorology driving mass and energy balance of the lowest perennial ice field of the Alps: a case study, Cryosphere, 13, 1247–1265, https://doi.org/10.5194/tc-13-1247-2019, 2019.
L42, L54: Some references missing here
L98: It would be useful to give some numbers that quantify this ‘rapid’ loss
L104: ‘massive’ is unclear, can you be more explicit?
L111-113: sentence structure needs revision.
Citation: https://doi.org/10.5194/egusphere-2026-3512-RC2 -
RC3: 'Comment on egusphere-2026-3512', Anonymous Referee #3, 21 Aug 2026
reply
The manuscript “A comprehensive TLS-based framework for cave ice monitoring under adverse surface conditions: application at Scărișoara Ice Cave” by Šupinský et al. presents a detailed investigation of cave ice development at Scărișoara Ice Cave in Romania with focus on the methodology (terrestrial laser scanning) needed to calculate ice volumes as accurately as possible. Although this is quite a niche topic, which will likely attract less readers, I find this work interesting and think it is a nice and also new contribution suitable for “The Cryosphere”.
The manuscript clearly focuses on the methodology and I think the authors did a good job in describing their work extremely accurately. However, I think the manuscript could benefit from some additional information not specifically related to the methodology.
“Romania” should be added to the title.
It would be helpful to describe in 1-2 sentences why their work is important and why ice caves should be monitored. Of course it is interesting to do it but what is broader value of doing it? In line 31 they mention the loss of paleoclimatic information. Is there anything else?
I think most readers are not super familiar with ice caves. It could be helpful to briefly define what an ice cave is, where you can find them, how many caves are known? Are these caves touristic caves and accessible to the public? Along with this it would be nice to have a photo of the cave somewhere in the introduction part. The only photos I could find are the ones in figure 7 and these are really small. Having one or two photos at the beginning would clearly help to easier introduce the readers to the investigation area and provide a general overview.
Can you briefly describe the main reasons for ice cave loss at Scărișoara? Rising temperatures? Less precipitation? Tourists? You talk about these things in general but it would be nice if you could provide some basic information for Scărișoara.
Again, I know the manuscript is already long and I don’t think it should be even longer, but maybe there is a way to shorten the methodology part slightly or summarize some information/figures. I really appreciate the effort the authors put into the detailed description but for readability it might be helpful to shorten the text.
Is the methodology suitable for monitoring in other caves? I assume yes since you have caves with similar conditions? This could be discussed towards the end of the paper to highlight the importance of the work?
In summary, I think the manuscript is suitable for publication in The Cryosphere after some revisions.
Citation: https://doi.org/10.5194/egusphere-2026-3512-RC3
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 146 | 51 | 19 | 216 | 15 | 12 |
- HTML: 146
- PDF: 51
- XML: 19
- Total: 216
- BibTeX: 15
- EndNote: 12
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
See the attached pdf.