Correlation of Ground Deformation Induced by the 6 February 2023 M7.8 and M7.5 Earthquakes in Turkey Inferred by Sentinel-2 and Critical Exposure in Gaziantep and Kahramanmaraş Cities

Round 1

Reviewer 1 Report

This paper proposes a very interesting correlation of the ground deformation with the critical exposure of the infrastructures of Gaziantep and Kahramanmaraş cities, affected by the 2023 Turkey earthquakes. The work presented by the authors is sound, but it has several shortcomings and requires several improvements.

The abstract offers concise and correct information on the remaining part of the article. The structure of the paper is logical, the methodology is clearly defined and it uses innovative models.

The manuscript lacks motivation and it is not very clear the purpose or contribution. The purpose and the objectives of the study must be definite more clearly (lines 88 - 92).

Also, some more international references could be used. For example: lines 51 – 55, 168 – 175.

There is an inconsistency in the text versus figures: lines 106 “Figures 2 and 3 respectively, along with important infrastructure information” – the important infrastructure information cannot be identified very clear in the figures. Please remove the text from the paper or emphasize the infrastructure information in the figures. The same is valid for lines 113 – 114 and figures 4 and 5.

Discussion and conclusion part should include a more detailed explanation and description of the results obtained within this paper. The paper, as well as the scientific community, would also benefit from an analysis of the data obtained: what do all the movements mean? What are their effects?

The work is very valuable and I recommend it to be published with minor revisions.

Author Response

This paper proposes a very interesting correlation of the ground deformation with the critical exposure of the infrastructures of Gaziantep and Kahramanmaraş cities, affected by the 2023 Turkey earthquakes. The work presented by the authors is sound, but it has several shortcomings and requires several improvements.

The abstract offers concise and correct information on the remaining part of the article. The structure of the paper is logical, the methodology is clearly defined and it uses innovative models.

The manuscript lacks motivation and it is not very clear the purpose or contribution. The purpose and the objectives of the study must be definite more clearly (lines 88 - 92).

Thank you for your comment. Indeed, we did not explain the purpose of the manuscript very clearly. The goal of this study is to examine the correlation between ground deformation, induced by the M7.8 and M7.5 earthquakes that occurred on 06 Feb. 2023 in Turkey, and the critical exposure of the infrastructures in Gaziantep and Kahramanmaraş cities. Specifically, we aim to estimate the extent of ground deformation at locations of critical infrastructures and identify infrastructures where the ground deformation is severe. The methodology used in this study is based on emergency mapping for cases of destructive events, utilizing Copernicus Sentinel-2 products and implementing the Normalized Cross Correlation algorithm (NCC).

Also, some more international references could be used. For example: lines 51 – 55, 168 – 175.

Thank you for your comment. We added more references.

There is an inconsistency in the text versus figures: lines 106 “Figures 2 and 3 respectively, along with important infrastructure information” – the important infrastructure information cannot be identified very clear in the figures. Please remove the text from the paper or emphasize the infrastructure information in the figures. The same is valid for lines 113 – 114 and figures 4 and 5.

Indeed, this was a mistake during the writing of the manuscript. The text has been corrected.

Discussion and conclusion part should include a more detailed explanation and description of the results obtained within this paper. The paper, as well as the scientific community, would also benefit from an analysis of the data obtained: what do all the movements mean? What are their effects?

Thank you for your comment. We have added more explanation regarding the results that we obtained and also added 2 Damage Maps of Gaziantep and Kahramanmaraş cities and compared them with the displacement and critical infrastructure exposure results.

The work is very valuable and I recommend it to be published with minor revisions.

Author Response File: Author Response.pdf

Reviewer 2 Report

In the Introduction some of the statements are well known. Thus they can be omitted without prejudice to understanding (together with the appropriate references). 

Ther is no substantive discussion of the results obtained.

No assumptions were made regarding the mosaic nature of surface displacement vector pattern, both in magnitude and in direction. 

In essence, only the measurement results themselves are presented with minimal comments

Author Response

In the Introduction some of the statements are well known. Thus, they can be omitted without prejudice to understanding (together with the appropriate references). 

Thank you for your comment. Indeed, we have removed some statements from the manuscript that are well-known, along with their corresponding references

There is no substantive discussion of the results obtained.

No assumptions were made regarding the mosaic nature of surface displacement vector pattern, both in magnitude and in direction. 

In essence, only the measurement results themselves are presented with minimal comments.

Thank you for your comment. You are correct in pointing out that the discussion of the results lacked detail. We have addressed this by providing additional comments and offering a clearer explanation regarding the ground displacement and its correlation with the critical infrastructures. Furthermore, we have included two Damage Maps of the cities and compared them with the results we obtained.

Author Response File: Author Response.pdf

Reviewer 3 Report

At present, there is no more snow in S2 image of your study area, please calculate it with the latest image.
In addition, vertical deformation is also important. Please also use SAR images to calculate vertical deformation.

Good to read.

Author Response

Comments and Suggestions for Authors

At present, there is no more snow in S2 image of your study area, please calculate it with the latest image.
In addition, vertical deformation is also important. Please also use SAR images to calculate vertical deformation.

Thank you for your comments. The images utilized in this study were the most recent ones available at the time of the earthquake, as this study focuses on emergency mapping of the event. Unfortunately, due to time constraints, it is not currently feasible to conduct new calculations. While there is no snow cover in the two cities that the study focuses on, we acknowledge the importance of using new S2 images to determine ground displacement for the broader region. Similarly, we agree that determining vertical deformation is crucial in such destructive events. In future works, we will certainly incorporate SAR processing to generate more comprehensive and precise results.

Comments on the Quality of English Language

Good to read.

Author Response File: Author Response.pdf

Reviewer 4 Report

You made an attempt to correlate the ground deformation following the two disastrous earthquakes nucleated on the EAF system with the critical exposure of the infrastructures of Gaziantep and Kahramanmaraş cities.

However, you included various information in the Introduction, which is not related to these two events and do not contribute in the quality of the paper.

In lines 37-46, the discussion about the term quake, the basic source parameters, the aftershocks etc seems to be rather of elementary seismology level text and not of a research article. I suggest removing them and the references 1,2,3, The same is valid for the text in lines 47-66, which are related to disastrous big events which have no relation with the last big events on the EAF zone. Remove this text and I suggest including information on the historical events and associated damage in this region. Lines 72-75 better to be removed.

Line 85: it is not very reliable if the ground displacement is more than a few meters [6]. I failed to find this reference. Either check the link or add another one. However, it would be good if you could explain the relation of the reliability with larger value (“more than few meters”).

Again, lines 96-114 include general information about the two cities for which, I cannot understand the relation with the two events (geography not seismology).

Figure 1 is a Google Earth map, which covers a very broad area. No information about the location of the EAFZ, the fault and the epicenter of the strongest (M>5.5) events of the sequence (main information related to the paper) are provided. Update this map properly.

Explain the need for the compilation of the maps 2-5, as it is not clear.

Line 136: Which is the relation between Pyrenees, Albroz, Zagros Mountains, Himalayas and the recent earthquakes? These are too far away from the EAF.

Lines 135-143: Either explain the reason for this text wish has almost no relation with the seismotectonic of the broader epicentral area, or remove it.

Line 166: Ref [18]. The correct reference for figure 6 is not the paper by Massoud et al 2011 but the paper of: Mascle, J., Benkhelil, J., Bellaiche, G., Zitter, T., Woodside, J., Loncke, L., 2000. Prismed II Scientific Party, marine geologic evidence for a Levantine–Sinai plate, a new piece of the Mediterranean puzzle. Geology 28, 779–782.

Line 184: Again you provide row information on the distribution of the heights/elevation without an interpretation of these information. Please add a few words.

Can you discuss your findings with the fault plane solutions?

Author Response

You made an attempt to correlate the ground deformation following the two disastrous earthquakes nucleated on the EAF system with the critical exposure of the infrastructures of Gaziantep and Kahramanmaraş cities.

However, you included various information in the Introduction, which is not related to these two events and do not contribute in the quality of the paper.

In lines 37-46, the discussion about the term quake, the basic source parameters, the aftershocks etc seems to be rather of elementary seismology level text and not of a research article. I suggest removing them and the references 1,2,3, The same is valid for the text in lines 47-66, which are related to disastrous big events which have no relation with the last big events on the EAF zone. Remove this text and I suggest including information on the historical events and associated damage in this region. Lines 72-75 better to be removed.

Thank you for your comment. We agree that the introduction has a lot of information that is well known, so we have made the corrections that you have proposed.

Line 85: it is not very reliable if the ground displacement is more than a few meters [6]. I failed to find this reference. Either check the link or add another one. However, it would be good if you could explain the relation of the reliability with larger value (“more than few meters”).

The text in Line 85 was a mistake during writing. The limitation of using SAR is that it does not provide measurements for the North – South component, which is important for our study. We have corrected the text and added the appropriate reference: Optical image matching techniques, are typically used to recover the two horizontal components of the 3D motion with magnitudes reaching from a fraction of the image pixel size to several dozen pixels [Stumpf, A.; Malet, J.P.; Puissant, A.; Travelletti, J. 2016. Monitoring of Earth Surface Motion and Geomorphologic Processes by Optical Image Correlation. Land Surface Remote Sensing, Elsevier, 2016, pp. 147-190, ISBN 9781785481055, https://doi.org/10.1016/B978-1-78548-105-5.50005-0]

Again, lines 96-114 include general information about the two cities for which, I cannot understand the relation with the two events (geography not seismology).

We agree that we have included a lot of information that is not important to the main subject of this study. We have removed the lines with unnecessary information.

Figure 1 is a Google Earth map, which covers a very broad area. No information about the location of the EAFZ, the fault and the epicenter of the strongest (M>5.5) events of the sequence (main information related to the paper) are provided. Update this map properly.

Thank you for your comment. We have updated the map with the EAFZ, the epicenters of the sequence and focused on our study area. 

Explain the need for the compilation of the maps 2-5, as it is not clear.

Maps 2-5 show the elevation and percent slope of the two cities. They are included to give a clear image of the topography. We added comments on the maps and we compared them with our findings in order to determine whether or not they are correlated to the ground displacement measurements.

Line 136: Which is the relation between Pyrenees, Albroz, Zagros Mountains, Himalayas and the recent earthquakes? These are too far away from the EAF.

In Section 3 we give general information regarding the movements of the tectonic plates involved in the event: the Anatolian, the Arabian and the Sinai plate. The formation of these mountain ranges is a result of the northward movement of the Arabian plate. However, it is extra information that is not important in our study, so we removed some of the text.

Lines 135-143: Either explain the reason for this text wish has almost no relation with the seismotectonic of the broader epicentral area, or remove it.

Thank you for your comment. We wrote this text to give information regarding the movements of the three plates involved in the destructive event: the Anatolian, the Arabian and the Sinai plate. The relative motions of these plates are the cause of seismicity. The intersection of these plates is a transform boundary named Hatay Triple Junction and it is the location of the two destructive earthquakes.

Line 166: Ref [18]. The correct reference for figure 6 is not the paper by Massoud et al 2011 but the paper of: Mascle, J., Benkhelil, J., Bellaiche, G., Zitter, T., Woodside, J., Loncke, L., 2000. Prismed II Scientific Party, marine geologic evidence for a Levantine–Sinai plate, a new piece of the Mediterranean puzzle. Geology 28, 779–782.

Indeed, this was a mistake. Thank you for your correction, we have updated it with the correct reference.  

Line 184: Again you provide row information on the distribution of the heights/elevation without an interpretation of these information. Please add a few words.

Thank you for your comment. We added text discussing the elevation and percent slope of the wider region that we are studying.

Can you discuss your findings with the fault plane solutions?

Thank you for your comment. We have added the EAFZ in the results of the wider region and added some comments regarding its correlation to the ground displacement.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The authors didn't esstentially revise the manuscript, especially in data results. Sentinel-2 provided many good images in the past three months. I strongly suggested you to use images sensed in April-May 2022 and April-May 2023.

No comment

Author Response

Thank you for your comments. It is important to note that the main focus of our study is the correlation of the ground displacement with the critical infrastructures of the two cities. In the images that we have used there is no snow covering the two cities, therefore snow cover in general does not hinder our calculations for Gaziantep and Kahramanmaras. We have verified that there is indeed no snow cover using data from meteorological stations of Meteostat as well (Gaziantep | Weather History & Climate | Meteostat , Kahramanmaras | Weather History & Climate | Meteostat ). Moreover, the snow mask that we have used is part of the Sentinel-2 products, since we have used atmospherically corrected images that provide snow cover masks. Finally, we have improved our results and made the correlation of ground displacement and critical infrastructures much clearer and with more detail.

Author Response File: Author Response.pdf

Reviewer 4 Report

Accept it

Author Response

Thank you for considering our work for a possible publication.