Detecting Geothermal Anomalies Using Multi-Temporal Thermal Infrared Remote Sensing Data in the Damxung–Yangbajain Basin, Qinghai–Tibet Plateau

Round 1

Reviewer 1 Report

This paper utilizes multi-temporal thermal infrared remote sensing data to detect and identify geothermal anomalies in the Dangxiong-Yangbajing geothermal area of the Tibetan Plateau as a typical example, and achieved some effective results. However, there are still some problems in the structure and discussion section. The following two important aspects should be improved in this manuscript.

 

1.     Section 4. Overall, there are no major problems with the methodology and results. However, the logical chain and order between the different sections should be adjusted. Firstly, it is feasible to divide the results into surface temperature results and extraction of anomalous zones, but the sections in 4.2 (4.2.1-4.2.6) and 4.2 are not containment of the results, but rather a logical relationship. In other words, some sections are not results but processes. For example, 4.2.2 and 4.2.3 should be placed in Chapter 3, not in the results. Of course, I understand that you get some results in these two processes, and this section could be considered as part of 4.2.4.

 

2.     Section 5.2. This part of the discussion is certainly important, but the discussion here is very premature. I would suggest that the authors consider extracting a thermal anomaly area or an existing geothermal system (e.g., the Yangbajing geothermal system) from their study. Through your current study, combined with the existing results of previous authors (temperature, reservoir, cap layer, hydrochemical characteristics, etc.), and then discussing the genesis mechanism, it will be very significant for the level of the article to be improved.

 

Overall, this manuscript has an interesting and pioneering work, however, given its current state, it is not suitable for publication. For the above reasons, I would suggest a "Moderate Revision".

 

Some specific comments are as follows:

Line 16, This is a wrong definition and appears badly in the first sentence. This is because geothermal energy is not necessarily high porosity and permeability, as in the case of hot dry rock.

Line 21-23, The sentence should be reorganised to introduce the proposed method and then explain the significance of the constituency.

Line 31, Should try to avoid this, these similar words in the beginning of the sentence, easy to cause ambiguity, please modify.

Line 34, makes up.

Line 35, Misrepresentation of "even".

Line 35, "Sweet spot" would be better.

Line 43-44, Lack of references.

Line 56-58, In fact, geothermal exploration in the region is not low compared to other regions, and probably the distribution is heterogeneous. The authors should have emphasised the importance of previous studies on the basis of listing them, rather than expressing an opinion without reviewing the literature.

Line 58, the DYB. The same below.

Line 67-88. This paragraph is not well written. Your purpose is to illustrate the feasibility of TIR remote sensing technology in detecting geothermal anomalies, you just need to state them separately and give examples, the paragraph is too redundant and should be re-condensed and rewritten.

Line 63-66, Combined into one sentence.

Line 99, This has already been mentioned and will not be repeated here.

Line 100-129, Section 2. In the geological background section, the presentation of the geology is too short. For example, what are the lithologies of the main thermal reservoirs in the study area and what are the distribution characteristics of these lithologies? For another, what are the temperatures of the reservoirs in the existing studies? Plus, are there similarities and differences in the cover layers in different regions? None of the above key information has been introduced by the authors and should be added. In addition, the distribution of faults should be put here for detailed introduction.

Line 106, Just use "m" and the same below.

Line 106, What is the point you want to make? It can be deleted for the “an overall elevation surpassing 4100 meters and”.

Line 109-111, Lack of necessary references.

Line 112-114, The correlation between fault activity and heat is an important topic. I am curious about the distribution of "active faults" here, please elaborate on this. Although I know that this is in the near N-S extensional zone, is there only "active fault" here? Or do you only show the "active fault" in Fig. 1? Please also indicate the location of other faults, such as reverse faults (which may be ancient faults).

Line 117-130, The information on geothermal power stations is detailed, but the presentation of language is a problem. This is mainly due to the lack of refinement of the language, such as too many short sentences or repetitiveness between different sentences; also, there is ambiguity in the expression of some sentences, such as the use of "it/these" at the beginning of many statements. In short, this paragraph should be rewritten.Line 137-141, Lack of necessary references.

Line 342, The position of the figure should follow the paragraph in which the original text first appeared; please revise throughout.

Line 344-345, Categorising the expression of anomalous areas is a very good way to do this. However, the way and basis for the categorisation should be detailed here first (why did you choose this criterion?), which is very important.

Line 354-360, Please note that this is not the result.

Line 362-363, Please note that this is a reference.

Line 370, There should be spaces between numbers and units, please revise throughout.

Line 395-398, Please elaborate on this statement, what specifically is unique about it?

Plus, there are two important flaws in the references section: the first is the lack of important references; the second is the incorrect formatting of the references.

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

 

 

The authors present an interesting methodological proposal for detecting geothermal anomalies using satellite infrared imagery. It is an interesting article that allows for an engaging read. Overall, the article is well-developed; however, there are certain points that need correction to enhance its quality due to the presence of some minor flaws.

To begin with, the introduction is adequately crafted to provide context for the article and the renewable resource needs such as geothermal energy. It also effectively explains the research's objectives and ideas.

In the "Geological Setting" section, the location and environment are described with precision and detail, offering a wealth of relevant data. Nevertheless, the text and symbology in Figure 1 are too small, making them hard to read. Enlarging the image or the elements for interpretation would help address this issue. This same error is noticeable in other figures throughout the document.

Moving on to the "Materials and Methods" section, the description of the Landsat 8 TIR sensor is accurate. However, it's advisable to mention the wavelength of Band 10 used in the research. Figure 2 is slightly small; the text should be of a larger size, similar to the rest of the text, for improved readability.

In the "Results" section, the explanation about why detection based on a single image is not the optimal choice and the use of mean winter LST distribution maps is provided. However, the process of generating these maps from Landsat 8 TIR images is not adequately explained. If photogrammetric techniques or other methodologies are employed to create heat maps, they should be mentioned. Additionally, the nature of the heat maps should be clarified—are they raster maps where each pixel represents LST, or are they vector maps?

The interpretation and analysis of winter LST are adequately developed. However, the process of water body removal is not detailed, particularly in terms of the software used. If GIS tools or another technique is used for this process, it would be valuable to mention it.

Figures 11, 12, and 14 are mentioned in the text after their inclusion; it's recommended to reference them prior to their appearance. The same applies to Figure 13. The legend's size in Figure 13 doesn't allow for clear visibility of the names of the thermal springs.

Lastly, it should be highlighted that the validation or verification of the methodology is based on the prior existence of thermal springs. However, it would be more accurate to demonstrate in-situ measurements using a complementary technique that compare the results obtained through remote sensing, in order to verify the accuracy of the map and the obtained outcomes.

Furthermore, some minor formatting and grammatical modifications are necessary:

Lastly, a significant portion of the document is written in the first person, such as "we innovatively…" or "We extracted…". For this type of document, writing in the third person is preferable. For example, the sentence "we innovatively adopt the Google Earth Engine (GEE) to retrieve the LST" can be transformed into the passive voice: "Google Earth Engine (GEE) was adopted to retrieve the LST in an innovative way." This change aligns the writing with the scientific article's standards. The phrasing should be modified throughout the document wherever possible.

Line 325: "detection[12]" add spacing "detection [12]"

Line 385: "anomalies[61]" add spacing "anomalies [61]"

Line 388: "detection[62,63]" add spacing "detection [62,63]"

Line 421: "methon"?? Did you mean "method"?

Finally, the text size in several figures (1, 2, 3, 5, 7, 8, 9, 10, 11, 12, and 14) is somewhat small. It would be advisable to make the text larger in these figures or increase the overall size of the figures themselves.

Some of these flaws are highlighted in the attached PDF.

I hope that these instructions contribute to improving the quality of the document.

 

 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This paper introduces a study focusing on identifying geothermal anomalies through multi-temporal land surface temperature (LST) analysis in the Damxung-Yangbajain basin of Qinghai-Tibet Plateau. Critical points and suggestions include:

1.           Methodological Details: Elaborate on terrain correction, altitude adjustment, and multi-temporal analysis techniques.

2.           Limitations and Future Scope: Address limitations and suggest avenues for future research.

3.           Language and Structure: Refine language and ensure smooth transitions for improved readability.

Overall, with the suggested improvements, the paper can effectively convey the study's contribution to geothermal anomaly detection and its potential impact on geothermal resource exploration.

Author Response

Please see the attachment.

Author Response File: Author Response.docx