Geothermal Linkage between a Hydrothermal Pond and a Deep Lake: Kuttara Volcano, Japan

Round 1

Reviewer 1 Report

This paper presents heat flux data on hydrothermal systems in Kuttara, Japan. There have been previous investigations of heat storage in the just Kuttara Lake that reported heat budget data. The paper comes up with interpretations of the budget of volcanic system in this setting.

 

Main issues that should be addressed:

The introduction fails to cite some important work on the volcanic system and makes inadequate statements that understanding of thermal system in volcano is lacking. There has been extensive work on this topic since the 1960's and the authors should look into papers by White, Fukutomi, Shepherd, Hurst and others to get a sense of what has been done. The current paper provides additional data but it fails to point out how it advances our understanding of the hydrological system in volcano. Therefore, it is a very localized paper. Tying in with work that has been done in this hydrological system would be helpful for the more general reader.

 

Why is the measured data of conductivity not included in the paper? It seems like there is data available and this would help put the geothermal flow in broader context and assess some of the statements made. Of course, it is the choice of the authors on how to split the data into publications.

 

The new data and contribution are geothermal system on Kuttara Volcano. However, it needs to be made clearer in the figures that these Kuttara Lake data are already published, especially because water temperature data would be used in Ref 9 (Fig. 4). Also, be sure to specify date label on the diagrams (Fig. 2 and Fig. 4), as the label "month/day/year" is confusing, In Figure 1, please arrange 3 figures, because Ohyunuma site is not clear on a large map. This will make it easier to read.

Author Response

Response to Reviewer 1 Comments

 

Point 1:

The introduction fails to cite some important work on the volcanic system and makes inadequate statements that understanding of thermal system in volcano is lacking. There has been extensive work on this topic since the 1960's and the authors should look into papers by White, Fukutomi, Shepherd, Hurst and others to get a sense of what has been done. The current paper provides additional data but it fails to point out how it advances our understanding of the hydrological system in volcano. Therefore, it is a very localized paper. Tying in with work that has been done in this hydrological system would be helpful for the more general reader.

 

Response 1:

 Thank you for your constructive comments.

According to your comments, as a review of studies on geothermal and hydrothermal systems below volcanoes or volcanic lakes, I added some papers (White, Hurst, Fukutomi) to “References”. However, I did not add Shepherd’s papers, because they did not deal with geothermal system or hydrothermal system, but with eruptive conditions of some volcanoes as in Nature. About water and chemical budgets of a volcanic lake, I added my paper about Lake Kussharo published in J. Hydrol., because the evaluation of groundwater inflow and outflow is connected to water and chemical budgets in a volcanic lake. I pointed out the advance of the present paper on Line 49-51 in the new version. I wrote the current condition of Kuttara Volcano related to the eruption’s disaster on Line 53-57 in the new version.

    I changed the layout in the first version of this paper, so that readers can more easily follow the observational and theoretical developments in this paper.

 

Point 2:

Why is the measured data of conductivity not included in the paper? It seems like there is data available and this would help put the geothermal flow in broader context and assess some of the statements made. Of course, it is the choice of the authors on how to split the data into publications.

 

Response 2:

   This time the EC25 data are used only for the pycnal stability of lake water. As a next step, when we deal with chemical budget of Lake Kuttara and chemical flux by the leaked groundwater in the lake, relations between EC25 and chemical components will be discussed.

 

Point 3:

The new data and contribution are geothermal system on Kuttara Volcano. However, it needs to be made clearer in the figures that these Kuttara Lake data are already published, especially because water temperature data would be used in Ref 9 (Fig. 4). Also, be sure to specify date label on the diagrams (Fig. 2 and Fig. 4), as the label "month/day/year" is confusing, In Figure 1, please arrange 3 figures, because Ohyunuma site is not clear on a large map. This will make it easier to read.




Response 3:

This time I used original data of vertical profiles in 2014. In the previous paper of Chikita et al. (2018), I showed 2015 and 2016 profiles in Figure 4. I explained the date label of "month/day/year" in the figure legend of Figure 3 in the new version. I separated Figure 1 into two figures, Figure 1 and Figure 2 to make clear the location of the Noboribetsu geothermal area.

Reviewer 2 Report

It is a interesting study, but the presentation and the structure of the paper must be improved to make it more Reader - friendly. I am missing details about the temperature measurements andn data collections. The figures must be improved eg the maps and the plotts

Comments for author File: Comments.pdf

Author Response

esponse to Reviewer 2 Comments

 

Point 1:

It is an interesting study, but the presentation and the structure of the paper must be improved to make it more Reader - friendly. I am missing details about the temperature measurements and data collections. The figures must be improved eg the maps and the plots

 

Response 1:

 Thank you for your constructive comments.

According to your comments, I changed the layout in the first version of this paper, so that readers could more easily follow the observational and theoretical developments in this paper.

As a review of studies on geothermal and hydrothermal systems below volcanoes or volcanic lakes, I added some papers (White, Hurst, Fukutomi) to “References”. About water and chemical budgets of a volcanic lake, I added my paper about Lake Kussharo published in J. Hydrol., because the evaluation of groundwater inflow and outflow is connected to water and chemical budgets in a volcanic lake. I pointed out the advance of the present paper on Line 49-51 in the new version. I wrote the current condition of Kuttara Volcano related to the eruption’s disaster on Line 53-57 in the new version.

I am sorry I plotted the wrong data in Figure 3 in the previous version. Please see Figure 4 in the new version.

    I separated Figure 1 into two figures, Figure 1 and Figure 2 to make clear the location of the Noboribetsu geothermal area.

I revised the first version, according to your comments in the pdf file. I think I responded to all the comments in the pdf.

Reviewer 3 Report

The manuscript (MS) proposes to evalute the relation between Lake Kuttara and the geothermal area of Noboribetsu by the evaluation of the heat budget of the hydrothermal pond of Okunoyu and the heat storage change in the lower layer of Lake Kuttara. The results show that the geothermal input in Lake Kuttara could be connected to the western side of the geothermal field Noboribetsu and in particular by the deepest zone of Kuttara Volcano. Moreover the magnitude and variation of the heat flux from the lake may be an indicator of the volcano activity.

The Authors approach an interesting research topic, I appreciate the hard work of the authors, especially in terms of field surveys, unfortunately, the reading of the manuscript is not fluid and sometimes too many disorganized information does not permit to understand and deduce the results and the relative conclusions.

I suggest to reorganize the introduction and the results - discussions, often these paragraphs are confused and the use the terminology is messy. The figures are not clear and need improvements.

The proposed MS, in the present form, does not adhere the standards of the journal and I recommend Major-Major Revision.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 3 Comments

 

Point 1:

The manuscript (MS) proposes to evaluate the relation between Lake Kuttara and the geothermal area of Noboribetsu by the evaluation of the heat budget of the hydrothermal pond of Okunoyu and the heat storage change in the lower layer of Lake Kuttara. The results show that the geothermal input in Lake Kuttara could be connected to the western side of the geothermal field Noboribetsu and in particular by the deepest zone of Kuttara Volcano. Moreover the magnitude and variation of the heat flux from the lake may be an indicator of the volcano activity.

 

The Authors approach an interesting research topic, I appreciate the hard work of the authors, especially in terms of field surveys, unfortunately, the reading of the manuscript is not fluid and sometimes too many disorganized information does not permit to understand and deduce the results and the relative conclusions.

 

I suggest to reorganize the introduction and the results - discussions, often these paragraphs are confused and the use the terminology is messy. The figures are not clear and need improvements.

 

The proposed MS, in the present form, does not adhere the standards of the journal and I recommend Major-Major Revision.

 

Response 1:

 Thank you for your constructive comments.

According to your comments, I changed the layout in the first version of this paper, so that readers could more easily follow the observational and theoretical developments in this paper.

As a review of studies on geothermal and hydrothermal systems below volcanoes or volcanic lakes, I added some papers (White, Hurst, Fukutomi) to “References”. About water and chemical budgets of a volcanic lake, I added my paper about Lake Kussharo published in J. Hydrol., because the evaluation of groundwater inflow and outflow is connected to water and chemical budgets in a volcanic lake. I pointed out the advance of the present paper on Line 49-51 in the new version. I wrote the current condition of Kuttara Volcano related to the eruption’s disaster on Line 53-57 in the new version.

I am sorry I plotted the wrong data in Figure 3 in the previous version. Please see Figure 4 in the new version.

    I separated Figure 1 into two figures, Figure 1 and Figure 2 to make clear the location of the Noboribetsu geothermal area.

    You advised me to indicate the periods of temperature increases on Figure 4 in the previous version. However, the increases in June – December are clear in Figure 4 as mentioned in the text. So I did not revise the figure. Please see Figure 5 in the new version.

Except for this point I think I responded to all the comments in the pdf.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

I accept this version of the paper. There are only some minor things to correct in the Reference List regarding use of .,: and ;