The Importance of Solving Subglaciar Hydrology in Modeling Glacier Retreat: A Case Study of Hansbreen, Svalbard
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe Hansbreen glacier front position variability from April to December 2010 was estimated with two glacier-fjord models (one coupled glacier-fjord model of and one ice flow model Elmer/Ice). Subglacial hydrology is a crucial component in modeling the entire glacier-fjord system and the results demonstrated its application and the importance of accurate predictions of the glacier front position.
The findings of this study demonstrated that the model that incorporates subglacial hydrology exhibits a closer alignment with observations, indicating its superior accuracy in representing the underlying physical processes. The results could be applied to future research in the study area and could contribute to precise glacier fluctuations estimation in the Arctic and other cryospheric regions.
Abstract and Introduction
The main question was addressed by the research in the introduction.
Page 1 line 13: Please, insert the Keywords.
Introduction: The research is about the glacier-fjord system, please add some information about the fjord geometry (fjord bathymetry and subglacial topography).
Materials and Methods
The methods were sufficiently documented to allow replication studies.
The models represent the period April to December 2010. When the glacier velocities and weekly glacier front position data were obtained?
Results and discussion
The quality of the figures is satisfactory, except the Figure 5. The figure needs the legend.
Conclusions
The conclusions are reporting glacier flow estimation and are supported by the results.
Comments on the Quality of English Language
The paper is well written.
Author Response
Reviewer #1 Comments and Suggestions for Authors
(Author responses are written in blue)
The Hansbreen glacier front position variability from April to December 2010 was estimated with two glacier-fjord models (one coupled glacier-fjord model of and one ice flow model Elmer/Ice). Subglacial hydrology is a crucial component in modeling the entire glacier-fjord system and the results demonstrated its application and the importance of accurate predictions of the glacier front position.
The findings of this study demonstrated that the model that incorporates subglacial hydrology exhibits a closer alignment with observations, indicating its superior accuracy in representing the underlying physical processes. The results could be applied to future research in the study area and could contribute to precise glacier fluctuations estimation in the Arctic and other cryospheric regions.
We thank the reviewer for their time and constructive comments, which have helped us to improve the clarity and quality of our manuscript. We appreciate the opportunity to address these valuable suggestions.
Abstract and Introduction
The main question was addressed by the research in the introduction.
Page 1 line 13: Please, insert the Keywords.
Keywords:
Tidewater glacier modeling; subglacial discharge; frontal ablation; calving; submarine melting.
Introduction: The research is about the glacier-fjord system, please add some information about the fjord geometry (fjord bathymetry and subglacial topography).
We thank the reviewer for pointing this out.
L 82-90: “(...). Hansbreen is a polythermal tidewater glacier flowing southward that covers an area of about 57 km². It is about 16 km long with a low mean surface slope of around 1.8° on average along the central flowline (Grabiec et al., 2012). Its calving front is 1.5 km wide with a vertical face about 100 m thick at the central flowline, of which 50 to 60 m are below sea level. The seasonal retreat of Hansbreen usually starts in June/July and lasts until late autumn/early winter, and the average summer and winter fluctuations amount to -125 m and 79 m, respectively (Blaszczyk et al., 2021). As for Hansbukta, it is about a 2 km long bay, with a minimum depth of approximately 22 m recorded within the sill located at the fjord mouth. The maximum depth reaches around 77 m in a ~200 m-wide channel on the central-west side of the Hansbreen front (Cwiakala et al., 2018). (...)”
L 103-104: “Bedrock topography was inferred from ground-penetrating radar data (Grabiec et al., 2012, Navarro et al., 2014).”
Materials and Methods
The methods were sufficiently documented to allow replication studies.
The models represent the period April to December 2010. When the glacier velocities and weekly glacier front position data were obtained?
They were obtained in 2010. We have included this information in the manuscript for clarification:
L 96-98: “We use the gridded surface velocity data of Munoz-Hermosilla et al. (2024), which were obtained by applying Bayesian Kriging techniques (Pérez-Doña et al., 2023) on daily horizontal velocities measured at a set of stakes located along the glacier in 2010 (see blue dots in Figure 2).”
L 105-106: “We take the Hansbreen weekly front positions obtained in 2010 from time-lapse camera images processed and described in Otero et al. (2017).”
Results and discussion
The quality of the figures is satisfactory, except the Figure 5. The figure needs the legend.
We thank the reviewer for their suggestion. However, we believe that a legend is not necessary for Figure 5, as it is quite simple and all relevant information is provided in the figure caption:
“Meshgrid of the subglacial hydrology of Hansbreen in September, obtained with Model 1. The white areas indicate water activity beneath the glacier. The three discharging channels identified at the glacier front have been circled and numbered in orange.”
Conclusions
The conclusions are reporting glacier flow estimation and are supported by the results.
Comments on the Quality of English Language
The paper is well written.
New references included in the revised version of the mansucript:
CwiakaÅ‚a, J.; Moskalik, M.; Forwick, M.; Wojtysiak, K.; Gi Ë™zejewski, J.; Szczuci ´nski, W. Submarine geomorphology at the front of the retreating Hansbreen tidewater glacier, Hornsund fjord, southwest Spitsbergen. Journal of Maps 2018, 14, 123–134. https://doi.org/10.1080/17445647.2018.1441757.
Reviewer 2 Report
Comments and Suggestions for AuthorsDear authors,
Please, read the attached paaper.
Reviewer no. 3
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
