Dynamic Relationship Study between the Observed Seismicity and Spatiotemporal Pattern of Lineament Changes in Palghar, North Maharashtra (India)
Round 1
Reviewer 1 Report
The authors present interesting observations and ideas. The manuscript, however, presents infirm supports and lacks a reference even in the key statement for the authors’ assertion (e.g., Lines 554-555). I recommend that the authors revise a paragraph or add just a classic reference for the linkage between stress change and lineament density (LD). In addition, the figures and graphs are not enough to corroborate the authors’ ideas. The depth model in Figure 4, for instance, is not necessary because the authors only use depth information of the earthquake swarm: The authors provide transects profiles (HT-1 to 4; VT-1 to 4) at different sections in Figure 4, however, the profiles are not used anywhere in the manuscript but in the description of Figure 4 in the text; Figure 5 shows three geophysical parameters with the number of earthquakes, however, the authors did not provide reasons to select the two parameters though the two factors were used to demonstrate less relationship to the seismicity compared with the other (i.e., rainfall). Here are my comments and points that need to be modified and revised:
Line 23. Blank error? “… with the __ increasing frequency …”
Lines 35-37. Add references.
Lines 38-39. Add references.
Line 41. Add references.
Line 63. Where is section 1.2? There is only section, 1.1, in the introduction section. The numbering for section 1.1 is not necessary.
Lines 69-70. Provide a reference for the geological information of the Indian shield region.
Lines 116-125. Here are two topics: a brief introduction to the methodology employed in the study and the meaning of the seismicity. Reconstruction is needed.
Lines 122-125. The authors state the meaning of the observed seismicity. The earthquake swarm, however, is from the others’ work [45]. I recommend that the authors emphasize the relationship between the seismicity and the spatiotemporal pattern of lineaments observed by the authors as the title of this study.
Line 244. Specify the full name of IMD, and then use the abbreviation. e.g., Indian Meteorological Department (IMD)
Lines 416-418. Why do the authors select the two parameters in numerous geophysical parameters, surface skin temperature, and soil moisture content?
Lines 554-555. This statement should need a reference.
Line 569. “~6 x 15 km2” Use right a multiplication sign and square sign.
Lines 583-586: What are “two important geophysical parameters”? Specify again, the two factors, surface skin temperature, and soil moisture content, or reconstruct the sentence after removing the expression. The manuscript doesn’t provide much information on the two parameters though the authors say they are ‘important. This makes the authors’ strategy, not objective. See the comments for Lines 416-418.
Figure 1. The authors have to provide the source of the earthquake catalogue [45] in also the figure caption.
Figure 3. The reduction in SMI mentioned in Lines 335-336 is not distinguishable due to usage of the same color variation regardless of the minimum and maximum values of the period. I recommend the color palette with the fixed minimum and maximum through the period to present the SMI changes.
Figure 4. 1) The histogram of (a) is with a too low resolution. The title of the x-axis and the y-axis is not legible.
Figure 4. 2) Remove the gaps among bars in the histogram. A histogram doesn’t have a gap among bars because it represents continuous data.
Figures 5a and 5b. The legends and titles of the x-axis and the y-axis are not legible. Especially in (b).
Figure 5b. 1) Adjust ranges of the y-axis to present fluctuation of the blue graphs, considering the usual range of the surface skin temperature. The axis doesn’t need to start from 0 K (-273.1°C ).
Figure 5b. 2) Add the missing y-axis of the red graph.
Author Response
Point wise reply to the comments made by Referee #1
Reviewer#1
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Comments and Suggestions for Authors
Authors: Many thanks to the Referee for sparing time to read our manuscript and providing valuable comments/suggestion on our manuscript. We have revised our manuscript in view of the comments/suggestions of the Referee.
Comments:
The authors present interesting observations and ideas. The manuscript, however, presents infirm supports and lacks a reference even in the key statement for the authors’ assertion (e.g., Lines 554-555). I recommend that the authors revise a paragraph or add just a classic reference for the linkage between stress change and lineament density (LD). In addition, the figures and graphs are not enough to corroborate the authors’ ideas. The depth model in Figure 4, for instance, is not necessary because the authors only use depth information of the earthquake swarm: The authors provide transects profiles (HT-1 to 4; VT-1 to 4) at different sections in Figure 4, however, the profiles are not used anywhere in the manuscript but in the description of Figure 4 in the text; Figure 5 shows three geophysical parameters with the number of earthquakes, however, the authors did not provide reasons to select the two parameters though the two factors were used to demonstrate less relationship to the seismicity compared with the other (i.e., rainfall). Here are my comments and points that need to be modified and revised:
Authors: Many thanks for your valuable comments/suggestion. We have considered all the comments/suggestion in the revised manuscript. Following suggestions of the Referee, we have included some additional references in the revised manuscript.
Text is revised following your suggestions, we have also included few more related figures as per the suggestions of other two referees.
Depth related Figure 4 is changed now with new transects as earthquake catalogues are updated till Dec 2020, suggested by other two reviewers. So, we have kept the depth map, and newly created depth transect profiles are added in the manuscript in replace of earlier one. Concerned text are revised. We have added G-R diagram suggested by other referee and included discussion in the text.
The importance of selection of three geophysical parameters are included in the manuscript. Figure 5 in earlier version, is now Figure 7 in the revised manuscript, it changed due to addition of other figures in the manuscript. The related parameters changes and its associations with the updated earthquake swarm points are clearly demonstrated in the revised version of the manuscript. Updating earthquake swarm data availability until 2000 are included in the revised manuscript as suggested by other Referees.
Many thanks to the Referee for valuable suggestions/comments, which have helped us to revise the earlier version of the manuscript.
Queries and our replies are given below based on the following points and suggestions.
Line 23. Blank error? “… with the __ increasing frequency …”
Authors: Thanks for your query. We have removed the blank error in the concerned line.
Lines 35-37. Add references.
Lines 38-39. Add references.
Line 41. Add references
Authors: Please see the track version, we have added few additional references and restructured according to sentences that need references.
Line 63. Where is section 1.2? There is only section, 1.1, in the introduction section. The numbering for section 1.1 is not necessary.
Authors: Many thanks for your comments. We have included another section with merging of some text, remove in other sections as per the concerned section. Now we have 1.1. and 1.2 sections. Please see track change and clean version for details.
Lines 69-70. Provide a reference for the geological information of the Indian shield region.
Authors: Lines have changed in revised manuscript. Geological information to support the Indian Shield region is provided in the text.
Lines 116-125. Here are two topics: a brief introduction to the methodology employed in the study and the meaning of the seismicity. Reconstruction is needed.
Authors: Many thanks for your suggestions, methodology sections are improved and now restructured.
Lines 122-125. The authors state the meaning of the observed seismicity. The earthquake swarm, however, is from the others’ work [45]. I recommend that the authors emphasize the relationship between the seismicity and the spatiotemporal pattern of lineaments observed by the authors as the title of this study.
Authors: Many thanks for your suggestions, we have revised manuscript in the light of your suggestions. As suggested by the Referee we have now revised the text and emphasized the relationship between seismicity and spatiotemporal pattern of lineaments.
Line 244. Specify the full name of IMD, and then use the abbreviation. e.g., Indian Meteorological Department (IMD)
Authors: We have taken care of your suggestions.
Lines 416-418. Why do the authors select the two parameters in numerous geophysical parameters, surface skin temperature, and soil moisture content?
Authors: We have discussed the reason for the selection of parameters in the section 2.2.4. In addition, the method sections have been revised, with G-R diagram distribution concept that added in this revised manuscript as suggested by the other Referee. Methodology have been restructured and it is now discussed in the sections 2.2.4.
Lines 554-555. This statement should need a reference.
Authors: Many thanks for your suggestion. We have added reference as suggested by the Referee.
Line 569. “~6 x 15 km2” Use right a multiplication sign and square sign.
Authors: We have taken care of your suggestions.
Lines 583-586: What are “two important geophysical parameters”? Specify again, the two factors, surface skin temperature, and soil moisture content, or reconstruct the sentence after removing the expression. The manuscript doesn’t provide much information on the two parameters though the authors say they are ‘important. This makes the authors’ strategy, not objective. See the comments for Lines 416-418.
Authors: We have revised the text and have shown the importance of the selection of these parameters to study influence of swarm events.
Figure 1. The authors have to provide the source of the earthquake catalogue [45] in also the figure caption.
Authors: As suggested by the Referee, we have now included the source of earthquake catalogue in Figure 1 caption.
Figure 3. The reduction in SMI mentioned in Lines 335-336 is not distinguishable due to usage of the same color variation regardless of the minimum and maximum values of the period. I recommend the color palette with the fixed minimum and maximum through the period to present the SMI changes.
Authors: Many thanks for your suggestions, we have revised the maps based on the fixed maximum and minimum values and changes in all maps, and figure number is changed to 5 now due to addition of earlier figures. All five temporal maps of SMI are now revised and inserted in the manuscript, which are clearly present the SMI changes in the study regions.
Figure 4. 1) The histogram of (a) is with a too low resolution. The title of the x-axis and the y-axis is not legible.
Authors: Thanks for your suggestion. We have taken care of your suggestions. Please see the concerned figure. It is now Figure 6 with addition of 3D graph Fig. 6d distribution as the catalog is updated. Please see the related section.
Figure 4. 2) Remove the gaps among bars in the histogram. A histogram doesn’t have a gap among bars because it represents continuous data.
Authors: Thanks for your suggestions. We have considered and changed the gaps of bars that earlier present in the diagram, now it has been revised and inserted with the figures, similarly we have followed for other figures also.
Figures 5a and 5b. The legends and titles of the x-axis and the y-axis are not legible. Especially in (b).
Authors: The previous Figure 5a, 5b are deleted, and another reviewer suggested to split the figure not using two parameters in a single figure and suggested to consider previous rainfall data to check the swarm’s relationship of rainfall. Therefore, we have downloaded the continuous data from NASA-Giovanni to match the same period in these three parameters to compare changes with the earthquake swarm events. Three figures are newly prepared and added in the revised manuscript. The previous Figure 5 number is now as Figure 7. Please see section 3.6 of the revised manuscript
Figure 5b. 1) Adjust ranges of the y-axis to present fluctuation of the blue graphs, considering the usual range of the surface skin temperature. The axis doesn’t need to start from 0 K (-273.1°C).
Authors: Thanks for your suggestions, we have revised, and figures are now updated, as it is in total 3 in numbers as 7a, b, c.
Figure 5b. 2) Add the missing y-axis of the red graph.
Authors: Thanks, we have revised the figures as new data are added in the graphs are newly prepared. We have revised our manuscript in view of comments/suggestions of all three reviewers.
We hope that the Referee will appreciate our efforts in revising manuscript and the manuscript will be acceptable to the Referees and to the Editor.
Reviewer 2 Report
Dear authors,
I have gone through the manuscript and believe your work can be a significant contribution to earthquake scientists. The figures in the manuscript are mostly not readable and it's important to improve the readability. This has impacted the quality of manuscript presentation. I am unable to relate figures 2 and 3 (bar graph) with your findings. Please improve the readability of the figures. The research design and other contents of the manuscript are appropriate. I suggest minor revisions for the manuscript.
Good Luck
Author Response
Pointwise reply to the comments/suggestions made by the Reviewer#2
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Comments and Suggestions for Authors
Dear authors,
I have gone through the manuscript and believe your work can be a significant contribution to earthquake scientists. The figures in the manuscript are mostly not readable and it's important to improve the readability. This has impacted the quality of manuscript presentation. I am unable to relate figures 2 and 3 (bar graph) with your findings. Please improve the readability of the figures. The research design and other contents of the manuscript are appropriate. I suggest minor revisions for the manuscript.
Good Luck
Submission Date
03 November 2021
Date of this review
12 Nov 2021 07:40:08
Authors: Many thanks to you for sparing your time in reading our manuscript, we are happy to learn that you found our manuscript interesting. We have now revised the manuscript in view of all the suggestions/comments. We hope that the revised manuscript will be acceptable to you and to other Referees.
Comments:
- I have gone through the manuscript and believe your work can be a significant contribution to earthquake scientists.
Authors: We are happy to see your valuable comments about our manuscript. We hope the paper we written is long term due and identified the potential different mechanism probably involved in triggering the swarm activities in the studied areas. This research has been designed in a different way which is definitely a new direction and a significant contribution to earthquake scientists. We hope our paper manuscript will attract attention of scientific community working in shield and stable continent.
.
- The figures in the manuscript are mostly not readable and it's important to improve the readability. This has impacted the quality of manuscript presentation.
Authors: All the figures are newly prepared and revised or few of them are newly designed as per the suggestions received from you and other Reviewers. We have modified figures so that it should be clearly visible, and captions are readable. Some figures are split and considered the 2018 data especially in meteorological and geophysical part to check the status and its changing nature with the earthquake swarm events.
- I am unable to relate figures 2 and 3 (bar graph) with your findings. Please improve the readability of the figures.
Authors: Probably you have typo mistake in figures 2 and 3, the bar graphs are used in figure 5 a, b in earlier version, after suggestion received and new data consideration, previous 5a, bare deleted and 3 new figures are prepared to support the text (Figure 7a, b, and c). The quality of the Figures is improved. Please check our new plots. Moreover, all the figures are revised and saved in better resolution.
- The research design and other contents of the manuscript are appropriate
Authors: Thanks a lot for your comments on our manuscript. Some sections are revised or changed according to the design of this manuscript.
Reviewer 3 Report
Review of “Dynamics of Lineaments Retrieved from Satellite Data and 2 Their Association with Observed Seismicity in Palghar, North 3 Maharashtra (India)” by Nath et al.
The paper investigated a very interesting topic about lineaments retrieved from satellite data, investigated the earthquake depth (very shallow) spatial distribution also with very interesting checks along transects. Finally the authors investigated 3 atmospheric parameters from MERRA-2 to search a possible relationship with earthquake activity (they concluded that there is not an evident link, but I suggested instead a different reading of the results with possible anticorrelation link between rainfall and earthquakes rate). The topic is full compatible with Remote Sensing Journal and the investigated case studies is high interest for scientific community and the conclusion could be even very useful to conduct further studies and eventual take some action to protect population (in case of confirmation of reactivation of the region as proposed by this paper), so for all of this reasons I think the paper fully deserve to be published in Remote Sensing, but I would like to ask the authors several improvements in the paper. It would be wonderful if you could extend the analysis that you shown in Figure 2 for every years from 2000 to 2020 (just one day for each year). If you do, I suggest to leave the same picture as example of 2000, 2015, 2018, 2019 and 2020 and add another picture with graphs of sysntetic information such as the number of lineaments, the main direction (red line in rose diagram and you can selected just one of the two angles that you provided in the text), and lineament density, in function of the time (years) compare this with earthquakes in the same long interval (you do in the text in this version of the manuscript it would be nice to see some graphs of this integrating the analysis before a final acceptance of the paper. You can find other my major concern and minor points in the following.
major concern:
- A concern for the whole paper that I think require before a decision on the paper is a lack of checking of Completeness magnitude. In the text the author used also very low energy earthquakes (line 221 ML from 0.4), this required an accurate check of the completeness of the catalogue to get any reliable conclusions. Furthermore, you can check also if there is a variation from 2000 to 2020 as I expect an improvement of the seismic catalogue among the year (so a lower completeness magnitude).
- The paragraph 3.1 about the Regional Seismicity analysis is not sufficient. The most important concern is that the authors compared different time-length periods: 1702 to 1985 are 284 years; 1986 to 1999 are 14 years; 2000 to 2006 are 6 years. For Gutenberg-Richter, 1954 distribution of earthquake magnitude it is expected that in a shorter time window there are less (even no-one) earthquakes of larger magnitude, so I ask to the author to do a G-R distribution of the 24 events and insert, please in the manuscript. This can help to evaluate the seismicity rate and we can then try to see if the two more recent periods lack of larger events or this is compatible with what is expected from historical seismicity.
- Gutenberg B. and Richter C.F., 1954. Seismicity of the Earth and Associated Phenomena, 2nd ed. (Princeton, N.J.: Princeton University Press, 1954).
- Transect analysis of fig.4: this is a very much interesting analysis. I only have a small suggestion: why don’t you aligned the transect with the mean seimci fault lines (and perpendicular to this one)? Another possibility is to use the red-fit directions obtained by the figure 2a-e and their perpendicular directions.
- Comments on atmospheric parameters from MERRA-2 (lines 416-422). Sorry I not completely agree with this conclusion/reading, in fact at least for rainfall (and maybe also Soil Moisture) there seems to be a relation of anti-correlation. In fact, they shows an opposite trend.
- Furthermore, in line 438 you said that most of the past swarms occurred after monsoon time. Please note that in fig.5a you plot from January 2019 and maybe in the last part of 2018 there also could be a wide rain / monsoon.
minor points:
- Line 52. The “audible sounds” are reported only verbally by people or also recorded by some instrumentation, please?
- Figure 1a. The external frame with coordinates doesn’t have any sense for the left part (longitudes minor than 72°40’). Maybe you used to include the other figures, but I suggest you instead to produce separately the 3 figures and after assemble them in one picture with graphics software (ex. GIMP, Paint, etc...).
- Line 60-62. I think this sentence is not appropriate for introduction (because it is not abstract/Summary) so I think can be deleted or shift in Conclusions.
- Line 81. A typo: “Giovanni portal”
- Line 120. The sentence sound little bit strange to me, maybe just shift “ are”: “ ...how many of them are in shallow...”
- Line 167. Maybe it is better to start the sentence with “Furthermore”
- Line 168. I think the sentence lack of a verb, maybe: “PC1 best band selection was carried out basing” (maybe better than based if I read properly the sentence).
- Line 183. Maybe “anthropogenic” is better than “cultural”
- Line 197. There is an open bracket without close it. I think maybe you can remove also the year as the citation number than contain it.
- Line 219. Maybe you can just write “occurred” and not “was occurred”
- Line 251. Which earthquake, please specify (I mean the one of M3 occurred on 01-01-2000, right?)
- Line 252. Why you said that the orientation is NE-SE, do you mean NE-SW? I noticed that the SW quadrant is practically empty...
- Line 263. This value that you report here (1.04 km/km2) is in the whole map and not in the underlined by red square area (Dahanu), can you explain me, please? I noticed the same also in the following but I asked you just one time.
- Figure 2. I have a concern if it is better the order of the figure you chosed or put close each other the two analyses for the same day. I explain you the order using the present letter: a-f-b-g-c-h-d-i-e-j. This is because you explain in the text in this order the figure. Anyway, I am not sure and the picture could appear to confused alternating two techniques, so I share with the authors this “idea” but it is not a real request to change, just think what you found better.
- Line 283-284. I suggest to substitute “In the next,” by “Subsequently,” and shift “again” after resumed, so the sentence would be: Subsequently, the seismic swarm activities resumed again in August 2017.
- Line 302. “declined” instead of “decline”
- Line 310. I agree with the sentence of the authors and I would add that for what I know some studies found induced seismicity also in Netherlands (in the beginning a no-seismic hazard region) due to underground fluids injection.
- Line 335. I noticed that the value that you provided is the maximum one, please specify “maximum” in the sentence otherwise is wrong or add MAX as the following sentences.
- Figure 4 is a very interesting and good investigation. Only a minor: in the color legend please remove the “minus” sign because the depth is positive not negative. If this causes a problem because you have data with minus sign you can manually erase in the exported picture, but it cannot be published with such legend.
- Line 407. Also here: NASA-Giovanni
- Line 408. Why do you use a different area from the previous investigations? Can you provide an explanation or use the same area, please?
- Figure 5b. Sorry, I don’t agree for the superposition on the same axis of Soil Moisture Content with Skin temperature (SKT). In fact, the SKT represented with the value that starts from 0K induce the loss of information, as the temperature has a variation range that is shorter. I have two alternative suggestions to address this problem: 1) divide into two distinctive graphs the two parameters (so, totally 3 graphs in fig.5). 2) use the two axes for skin temperature and Soil moisture and the earthquakes can be just superposed and you can write the number of earthquakes above each green bar (as you do for moisture).
- Line 464. Maybe it is better to start with “Instead,” and not “But”
- Line 465. “have been under ongoing stresses” maybe is right in English, but sound hard to read, if you found an easier sentence I think it is better.
- Line 500 it is presumed
- Line 537 Giovanni
Author Response
Pointwise reply to the comments/suggestions made by the Reviewer#3
Review Report Form
Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes |
Can be improved |
Must be improved |
Not applicable |
|
Does the introduction provide sufficient background and include all relevant references? |
(x) |
( ) |
( ) |
( ) |
Is the research design appropriate? |
( ) |
(x) |
( ) |
( ) |
Are the methods adequately described? |
(x) |
( ) |
( ) |
( ) |
Are the results clearly presented? |
( ) |
(x) |
( ) |
( ) |
Are the conclusions supported by the results? |
( ) |
(x) |
( ) |
( ) |
Comments and Suggestions for Authors
Review of “Dynamics of Lineaments Retrieved from Satellite Data and 2 Their Association with Observed Seismicity in Palghar, North 3 Maharashtra (India)” by Nath et al.
Authors: Thanks a lot for your valuable time in reading our manuscript and providing valuable comments/suggestions. We are happy to submit the revised version to you for your final evaluation. We have made our efforts to revise the text and figures, and other parts of the manuscript in view of the comments/suggestions of the Referee.
- The paper investigated a very interesting topic about lineaments retrieved from satellite data, investigated the earthquake depth (very shallow) spatial distribution also with very interesting checks along transects. Finally the authors investigated 3 atmospheric parameters from MERRA-2 to search a possible relationship with earthquake activity (they concluded that there is not an evident link, but I suggested instead a different reading of the results with possible anticorrelation link between rainfall and earthquakes rate). The topic is fully compatible with Remote Sensing Journal and the investigated case studies is high interest for scientific community and the conclusion could be even very useful to conduct further studies and eventual take some action to protect population (in case of confirmation of reactivation of the region as proposed by this paper), so for all of this reasons I think the paper fully deserve to be published in Remote Sensing, but I would like to ask the authors several improvements in the paper.
Authors: Thanks a lot for your critical evaluation and sending us your valuable suggestions which helped us to revise our manuscript. The meteorological and geophysical parameters are again downloaded from NASA Giovanni portal and considered the period a bit longer started from Jan 2018 to the end of 2020 was considered to check the relation of those with the earthquake swarm events. And we observed possible changes, some are changed with the swarm activity, and some are occurred in delaying, but have observed changes with the time when earthquakes swarms are in progress in the affected areas. The title of our manuscript is now revised and fully matched with the text matter that we discussed in the manuscript.
We are grateful to you for your constructive suggestions and comments which helped us a lot to improve our manuscript in the present form. We are happy to incorporate your comments and suggestions in our manuscript. Please go through the revised version of the submitted manuscript. The graphical abstract is revised, supplementary file related to Figure 7, three geophysical parameters data are submitted with this manuscript as it is freely access by the readers to its further uses.
- It would be wonderful if you could extend the analysis that you shown in Figure 2 for every years from 2000 to 2020 (just one day for each year). If you do, I suggest to leave the same picture as example of 2000, 2015, 2018, 2019 and 2020 and add another picture with graphs of synthetic information such as the number of lineaments, the main direction (red line in rose diagram and you can selected just one of the two angles that you provided in the text), and lineament density, in function of the time (years) compare this with earthquakes in the same long interval (you do in the text in this version of the manuscript it would be nice to see some graphs of this integrating the analysis before a final acceptance of the paper. You can find other my major concern and minor points in the following.
Authors: Thanks for your comments. We have extended the analysis as you suggested. Figure 1 is now split in two ways. As shown in Figure 1 and 2 based on the appropriate section design. Previous Fig. 2 is now Figure 3. We have adjusted it. The graph has been added based on the suggestions and considered similar time span, LD and lineaments frequency changes of broad regions are compared with swarm regions and find out the association with earthquake activity. Pease see the graphs and revised manuscript for your final evaluations.
We have taken care of all other details observations regarding major and minor concerns in our revised manuscript.
major concern:
- A concern for the whole paper that I think require before a decision on the paper is a lack of checking of Completeness magnitude. In the text the author used also very low energy earthquakes (line 221 ML from 0.4), this required an accurate check of the completeness of the catalogue to get any reliable conclusions. Furthermore, you can check also if there is a variation from 2000 to 2020 as I expect an improvement of the seismic catalogue among the year (so a lower completeness magnitude).
Authors: Thanks for your critical evaluation. We have revised the manuscript according to the completeness of earthquake magnitude. Catalogue of the earthquake swarm events are fully checked, and related values are fine and proper description is given in the concerned sections. Yes, thanks for your suggestions. We have checked also, there is subtle variation in earthquakes swarms’ event which is significantly increased compared to the past year, and several meteorological and geophysical parameters are changes with the swarm events. Lineaments changes have been specifically observed in swarm regions with the compared accordingly with the previous one, Swarm Ares lineaments are subset and density have generated and found increasing tendency compared to surrounding broad regions. The presence of surrounding faults along the swarm areas are helped a lot to tightly clustered those shear number of earthquakes, resulted as swarm activity.
Seismic catalogue of large database is not provided with the existing historical catalog table A1, as it a continuation of datasets. After a long gap the regions is experiencing this activity.
- The paragraph 3.1 about the Regional Seismicity analysis is not sufficient. The most important concern is that the authors compared different time-length periods: 1702 to 1985 are 284 years; 1986 to 1999 are 14 years; 2000 to 2006 are 6 years. For Gutenberg-Richter, 1954 distribution of earthquake magnitude it is expected that in a shorter time window there are less (even no-one) earthquakes of larger magnitude, so I ask to the author to do a G-R distribution of the 24 events and insert, please in the manuscript. This can help to evaluate the seismicity rate and we can then try to see if the two more recent periods lack of larger events or this is compatible with what is expected from historical seismicity.
- Gutenberg B. and Richter C.F., 1954. Seismicity of the Earth and Associated Phenomena, 2nd ed. (Princeton, N.J.: Princeton University Press, 1954).
Authors: Thanks for your valuable suggestion, we have checked the completeness of earthquake magnitude and prepared G-R distribution based on the swarm data points. But due to less reliable source and non-stationary records of the historical earthquake data, we are not considered in the GR distributing. b-value is observed 1 with standard deviation is added. Graphs are prepared as you suggested. Please see the concerned section for G-R plot. The description provided in text regarding the G-R is available in the manuscript. Please go through the revised track change and clean version.
- Transect analysis of fig.4: this is a very much interesting analysis. I only have a small suggestion: why don’t you aligned the transect with the mean seismic fault lines (and perpendicular to this one)? Another possibility is to use the red-fit directions obtained by the figure 2a-e and their perpendicular directions.
Authors: Thanks for your valuable suggestions, we have prepared 3D mesh diagram of the depth data which tells the data variations, along t=with our previously created transects in different directions across the swarm regions. Faults lines aligned depth variations are discussed in the text, and extra figures in that directions are not prepared. Hope depth changes are found out well as different parts. NPS and E-W checking and depth data distributions are prepared and inserted in the manuscript.
- Comments on atmospheric parameters from MERRA-2 (lines 416-422). Sorry I not completely agree with this conclusion/reading, in fact at least for rainfall (and maybe also Soil Moisture) there seems to be a relation of anti-correlation. In fact, they show an opposite trend.
Authors: Thanks for your comments. We partially agree with your views, it is not anticorrelation, we have observed the enhancement activity of meteorological and geophysical parameters with the swam activities in these areas after the monsoon in previous year, but recently it moves and increased with the earthquake events in a particular time periods, then it decreases while earthquakes have high rate. The text is revised accordingly, please go through the concerned part of the manuscript.
- Furthermore, in line 438 you said that most of the past swarms occurred after monsoon time. Please note that in fig.5a you plot from January 2019 and maybe in the last part of 2018 there also could be a wide rain / monsoon.
Authors: Thanks for your careful observation. We have reconsider and revise the graphs according to previous data and later data, till 2020 Dec along with past from 1 Jan 2018. And observed the similar wide rain was occurred in that area as we are closely observed the swarm regions. Soon after the monsoon, earthquake started. And in recent it coincided with the rainfall, therefore, we have added and prepared three graphs (see Fig 7a, b, c) to support our observations.
minor points:
Authors: As the entire manuscript is revised, the page and line numbers have changed accordingly. And due to major text adjustment, we suggest you please go through both version clean and track mode version to find out the change which are shown in red and blue color text.
- Line 52. The “audible sounds” are reported only verbally by people or also recorded by some instrumentation, please?
Authors: Thanks, this has been reported by instruments and confirmed by local, concerned text in the manuscript are revised.
- Figure 1a. The external frame with coordinates doesn’t have any sense for the left part (longitudes minor than 72°40’). Maybe you used to include the other figures, but I suggest you instead to produce separately the 3 figures and after assemble them in one picture with graphics software (ex. GIMP, Paint, etc...).
Authors: Thank you for pointing it. Frames are separated. It was mistakenly merged and extended with the others. It is now improved, and quality are maintained. Layout has been prepared again. See Fig. 1
- Line 60-62. I think this sentence is not appropriate for introduction (because it is not abstract/Summary) so I think can be deleted or shift in Conclusions.
Authors: Thanks, it deleted from introduction and considered in the conclusion part with the other text.
- Line 81. A typo: “Giovanni portal”
- Authors: sorry for our lapses, typo mistake is removed and corrected throughout the manuscript. Is now showing Giovanni portal
- Line 120. The sentence sound little bit strange to me, maybe just shift “are”: “ ...how many of them are in shallow...”
Authors: we have taken care of this.
- Line 167. Maybe it is better to start the sentence with “Furthermore”
Authors: we have taken care of this.
.
- Line 168. I think the sentence lack of a verb, maybe: “PC1 best band selection was carried out basing” (maybe better than based if I read properly the sentence).
Authors: we have taken care of this.
- Line 183. Maybe “anthropogenic” is better than “cultural”
Authors: we have taken care of this.
- Line 197. There is an open bracket without close it. I think maybe you can remove also the year as the citation number than contain it.
Authors: we have taken care of this.
- Line 219. Maybe you can just write “occurred” and not “was occurred”
Authors: we have taken care of this.
- Line 251. Which earthquake, please specify (I mean the one of M3 occurred on 01-01-2000, right?)
Authors: Yes, you are right, we have added it and mentioned in the missing part as it was not written in early version. Now it is clearly represented the time.
- Line 252. Why you said that the orientation is NE-SE, do you mean NE-SW? I noticed that the SW quadrant is practically empty...
Authors: Thanks, it is NE-SW, it was a bit spelling mistake in that text. Corrected in the revised version.
- Line 263. This value that you report here (1.04 km/km2) is in the whole map and not in the underlined by red square area (Dahanu), can you explain me, please? I noticed the same also in the following but I asked you just one time.
Authors: we have taken care of this. we have considered your idea, and swarms regions lineaments separated and prepare similar period map which have similar direction movements with broad regions. Comparison graph is attached in the manuscript and text are revised according to the graph.
- Figure 2. I have a concern if it is better the order of the figure you chose or put close each other the two analyses for the same day. I explain you the order using the present letter: a-f-b-g-c-h-d-i-e-j. This is because you explain in the text in this order the figure. Anyway, I am not sure and the picture could appear to confused alternating two techniques, so I share with the authors this “idea” but it is not a real request to change, just think what you found better.
Authors: Thanks a lot for your suggestion, we have revised the text, and figures are now side by side with lineaments and density changes, and numbered sequentially, as a, b, for 2000, c, d for 2015, and so on.
- Line 283-284. I suggest to substitute “In the next,” by “Subsequently,” and shift “again” after resumed, so the sentence would be: Subsequently, the seismic swarm activities resumed again in August 2017.
Authors: Thanks, sentences are adjusted with revised text.
- Line 302. “declined” instead of “decline”
Authors: It is corrected, considered “declined”.
- Line 310. I agree with the sentence of the authors and I would add that for what I know some studies found induced seismicity also in Netherlands (in the beginning a no-seismic hazard region) due to underground fluids injection.
- Authors: Thanks for your suggestion. We have added particular reference from Netherland events which having underground fluid injection. Reference added in the list and concerned text are revised and cited. Please see citation list number 100.
- Line 335. I noticed that the value that you provided is the maximum one, please specify “maximum” in the sentence otherwise is wrong or add MAX as the following sentences
Authors: Thanks, maximum considered, and text are fine now. Line number has changed. Please go through the clean version as it is extensively edited, we are not showing you line number, as it will change in clean version.
- Figure 4 is a very interesting and good investigation. Only a minor: in the color legend please remove the “minus” sign because the depth is positive not negative. If this causes a problem because you have data with minus sign you can manually erase in the exported picture, but it cannot be published with such legend.
Authors: Thanks for your suggestion. We have changed text and minus sign are removed from figures, and sub-figures. Yes, depth is positively showing in current form. Figure 4 is now Figure 6, due to addition of other figures.
- Line 407. Also here: NASA-Giovanni
Authors: Thanks, it is changed, and typo mistake is fixed.
- Line 408. Why do you use a different area from the previous investigations? Can you provide an explanation or use the same area, please?
Authors: It was bit decimal related problem while it is not given during used defined choice. We have now considered the same extension that reported earlier text, now use that extension for data downloading and processing. Both reported are same area. Problem resolved. Please see the text, and figures are newly prepared with data start from Jan 2018 to Dec 2020.
- Figure 5b. Sorry, I don’t agree for the superposition on the same axis of Soil Moisture Content with Skin temperature (SKT). In fact, the SKT represented with the value that starts from 0K induce the loss of information, as the temperature has a variation range that is shorter. I have two alternative suggestions to address this problem: 1) divide into two distinctive graphs the two parameters (so, totally 3 graphs in fig.5). 2) use the two axes for skin temperature and Soil moisture and the earthquakes can be just superposed and you can write the number of earthquakes above each green bar (as you do for moisture).
Authors: Thank you very much for your guidance. We have changed and spit the figures into three after addition of new data. Please see three graphs as 7a, b, c as numbering changed due to addition of other figures.
- Line 464. Maybe it is better to start with “Instead,” and not “But”
Authors: Thanks, we have taken care of this problem.
- Line 465. “have been under ongoing stresses” maybe is right in English, but sound hard to read, if you found an easier sentence, I think it is better.
Authors: Sentence revised and simplified as stress developed in the swarm areas. Text is revised. In addition, we inform to you that all other corrections or improvements could be find in the revised version highlighted in blue and red color text.
- Line 500 it is presumed
Authors: taken care
- Line 537 Giovanni
Authors: It is corrected as Giovanni.
Round 2
Reviewer 1 Report
The authors addressed the reviewer's comments in the first round of revisions and the paper has been improved. Especially, the changes to the figures and their captions become helpful. In my opinion, the manuscript is ready to be published at this stage.
Author Response
Many thanks for your remark, we are happy to see your recommendation about our manuscript.
Thanks
Reviewer 3 Report
I thank you very much the authors to had considered all my suggestions and points and revising accordingly the manuscript. The manuscript now is improved and more clear. I appreciate the introduction of citation of the news in Nature-India with interviews to the authors of this paper providing crucial important information about the nature of the source of the swarm in Palghar: tectonic or induced by fluids from Monsoon? I think that this point is so important that I would like to ask to the authors to add another point to the 7 that they already provide in the discussion that clearly says what is the proof from this study to such an important question. I think that with the analysis provided in Fig. 8 you can proof that this study confirms the fluid-monsoon induced earthquakes in this area. Reading again the manuscript I found several points to be improved, but most of them are minor or just English rewrite.
minor points:
- Figure 1d. The horizontal axes of both panels lack the ticks and labels, please add. It is not essential but it also would be better that right panel and left panel has the same height (as both goes from 0 to 10 km depth).
- Line 98. I think it is “shows” not “show”
- Line 86-87. Sorry, the sentence is not so clear (I understood what you mean, but I think it can be improved). I think “that” (after “As we know,”) can be removed. After three maybe is better to insert parameters. Anyway, it is not so clear why you said the earthquake location is normally in or around the fault line (I agree, sure) and the selection of three parameters... maybe there is a sentence fragment that was lost?
- Line 102. Please specify route/highway/railway or what is it after NH-8.
- Line 154. The inserted website brought me to the National Career Service of India Government... instead, the website indicated in line 150 is the right one, I think you can remove the second one ore replace with the proper link.
- Line 162. Maybe literature is singular because the literature than is composed by many papers and books
- Line 185. “observed in before” I think it is just “observed before”
- Line 225. Maybe “only” can be removed.
- Line 249. I think you are referring to figure 7
- Line 250. Maybe “transferred into ENVI” is better than “transformed” or another way could be saying that the images are processed by ENVI 5.3 to construct...
- Line 267, 269 and 271. Sorry, also here seems Figure 8 not 7.
- Line 301-304. Sorry the old with the new sentence does not flow well in English: Due to.... except 24 ... are considered... please revise the sentence changing some connections or verbs.
- Line 309. I would suggest to reformulate the sentence in the following way: “The estimated Mc assumes of a power-law Gutenberg–Richter relationship and the magnitude where the first derivative of the frequency–magnitude curve has its maximum is taken as the Mc value.”
- Line 316. Please insert the uncertainness for the b value. I have anyway some concern about the G-R graph. I noticed that the higher magnitude events are under the fit. This could be due to a too-short time for the considered events (as higher magnitude are less frequent) or a bad fit. Can you please clarify or just insert a similar consideration in the paper, please? Thank you, a lot, to have got and implemented this suggestion of Gutenberg-Richter distribution.
- Line 336. What do you mean by “update”, please?
- Line 380. Between the two sentences (region, / we observed) I would suggest adding a conjunction like : “and” / “therefore” or something else to link the two sentences
- Line 388. “this” is a singular word and “continuations” is plural, maybe one needs to be changed...
- Figure 5. Thank you very much to have taking into account my suggestion. I have only concern about some error bars: why they are out of value? For Example for 2000/orange(broad region) the bar is totally upside, for 2019 and 2020, the blue swarm region the upper tick is in the middle..)... and what do they represent? +/-1 standard deviation or interquartile range?
- Line 421. I would like the authors to say something more, for example, I see that in the broad region the trend of LDmax is practically monotonically increasing (point of 2020 is slightly lower, but we can suppose it is due to uncertainness as its variation with respect to 2019 is not significant), while Swarm area seems to oscillate (2.2 lower to 2.1 up to 2.3, low to 2.1 and up to 2.2...). If you provide a possible explanation/interpretation it would be great too.
- Line 567. Maybe it is not “However” but “In fact,” as this sentence confirms the previous considerations...
- Line 571-573. Sorry there is English problem in this sentence that in the present form has no sense... if you substitute “that” with “was” I think is perfect.
- Line 573. “occurred” need to be placed before “earthquakes”
- Line 573-575. Sorry, I don’t understand what you mean by this sentence (together with the previous one). I don’t know if it is for poor English of these two sentences or conceptual problem. For example, “are not well documented” do you mean “are not detected/localized”? In historical time is good to speak about documented earthquakes, while in the “instrumental era” we can say not-detected or not localised....
- Line 583. Maybe you can say “maximum in their number”.
- Line 718. A question please: The two months delay could be related to the time of percolation of the fluids from the first layer of the soil (10 cm) to the lower depth of some km where most of the earthquakes are localised (that you provide in Figure7 and it is around 3km? If the authors think this could be an explanation you can introduce a sentence with a reference from literature to estimate this time (or provide a calculus of estimation of such time: I don’t know).
Author Response
REPLY TO THE COMMENTS MADE BY REFEREE #3
I thank you very much the authors to had considered all my suggestions and points and revising accordingly the manuscript. The manuscript now is improved and more clear. I appreciate the introduction of citation of the news in Nature-India with interviews to the authors of this paper providing crucial important information about the nature of the source of the swarm in Palghar: tectonic or induced by fluids from Monsoon? I think that this point is so important that I would like to ask to the authors to add another point to the 7 that they already provide in the discussion that clearly says what is the proof from this study to such an important question. I think that with the analysis provided in Fig. 8 you can proof that this study confirms the fluid-monsoon induced earthquakes in this area. Reading again the manuscript I found several points to be improved, but most of them are minor or just English rewrite.
Authors: Many thanks to the Referee for reading our manuscript carefully and providing comments/suggestions to improve our manuscript further. Now we have revised our manuscript in view of the minor comments as suggested by the Referee.
minor points:
- Figure 1d. The horizontal axes of both panels lack the ticks and labels, please add. It is not essential but it also would be better that right panel and left panel has the same height (as both goes from 0 to 10 km depth).
- Line 98. I think it is “shows” not “show”
- Line 86-87. Sorry, the sentence is not so clear (I understood what you mean, but I think it can be improved). I think “that” (after “As we know,”) can be removed. After three maybe is better to insert parameters. Anyway, it is not so clear why you said the earthquake location is normally in or around the fault line (I agree, sure) and the selection of three parameters... maybe there is a sentence fragment that was lost?
- Line 102. Please specify route/highway/railway or what is it after NH-8.
- Line 154. The inserted website brought me to the National Career Service of India Government... instead, the website indicated in line 150 is the right one, I think you can remove the second one ore replace with the proper link.
- Line 162. Maybe literature is singular because the literature than is composed by many papers and books
- Line 185. “observed in before” I think it is just “observed before”
- Line 225. Maybe “only” can be removed.
- Line 249. I think you are referring to figure 7
- Line 250. Maybe “transferred into ENVI” is better than “transformed” or another way could be saying that the images are processed by ENVI 5.3 to construct...
- Line 267, 269 and 271. Sorry, also here seems Figure 8 not 7.
- Line 301-304. Sorry the old with the new sentence does not flow well in English: Due to.... except 24 ... are considered... please revise the sentence changing some connections or verbs.
- Line 309. I would suggest to reformulate the sentence in the following way: “The estimated Mc assumes of a power-law Gutenberg–Richter relationship and the magnitude where the first derivative of the frequency–magnitude curve has its maximum is taken as the Mc value.”
- Line 316. Please insert the uncertainness for the b value. I have anyway some concern about the G-R graph. I noticed that the higher magnitude events are under the fit. This could be due to a too-short time for the considered events (as higher magnitude are less frequent) or a bad fit. Can you please clarify or just insert a similar consideration in the paper, please? Thank you, a lot, to have got and implemented this suggestion of Gutenberg-Richter distribution.
- Line 336. What do you mean by “update”, please?
- Line 380. Between the two sentences (region, / we observed) I would suggest adding a conjunction like : “and” / “therefore” or something else to link the two sentences
- Line 388. “this” is a singular word and “continuations” is plural, maybe one needs to be changed...
- Figure 5. Thank you very much to have taking into account my suggestion. I have only concern about some error bars: why they are out of value? For Example for 2000/orange(broad region) the bar is totally upside, for 2019 and 2020, the blue swarm region the upper tick is in the middle..)... and what do they represent? +/-1 standard deviation or interquartile range?
- Line 421. I would like the authors to say something more, for example, I see that in the broad region the trend of LDmax is practically monotonically increasing (point of 2020 is slightly lower, but we can suppose it is due to uncertainness as its variation with respect to 2019 is not significant), while Swarm area seems to oscillate (2.2 lower to 2.1 up to 2.3, low to 2.1 and up to 2.2...). If you provide a possible explanation/interpretation it would be great too.
- Line 567. Maybe it is not “However” but “In fact,” as this sentence confirms the previous considerations...
- Line 571-573. Sorry there is English problem in this sentence that in the present form has no sense... if you substitute “that” with “was” I think is perfect.
- Line 573. “occurred” need to be placed before “earthquakes”
- Line 573-575. Sorry, I don’t understand what you mean by this sentence (together with the previous one). I don’t know if it is for poor English of these two sentences or conceptual problem. For example, “are not well documented” do you mean “are not detected/localized”? In historical time is good to speak about documented earthquakes, while in the “instrumental era” we can say not-detected or not localised....
- Line 583. Maybe you can say “maximum in their number”.
- Line 718. A question please: The two months delay could be related to the time of percolation of the fluids from the first layer of the soil (10 cm) to the lower depth of some km where most of the earthquakes are localised (that you provide in Figure7 and it is around 3km? If the authors think this could be an explanation you can introduce a sentence with a reference from literature to estimate this time (or provide a calculus of estimation of such time: I don’t know).
Authors: Now we have taken care of all the minor points as suggested by the Referee #3. Sorry for our lapses, at the same time we are very grateful to the Referee for reading our manuscript carefully. We hope that the revised manuscript will be acceptable to the Referee and to the Editor.