Geometric Variation in the Surface Rupture of the 2018 Mw7.5 Palu Earthquake from Subpixel Optical Image Correlation
Round 1
Reviewer 1 Report
The present manuscript aims to study the geometric variation across the Palu Fault ruptured on 28 September 2018, based on satellite images. Overall, I think this is an interesting paper that has a significant amount of data with interesting implications. I think that their analysis is solid and through this methodology, the authors can describe their goal.
However, I do have three major comments
- I would expect at least one paragraph and an extra figure describing the geological characteristic of the study area, considering that the geometry of a fault trace is affected by this factor as well
- In general, the figures of the manuscript are not sufficient. Within the attached manuscript you will find my relevant recommendations
- Finally the discussion of the manuscript is too short. More specific, without a better and stronger discussion the entire manuscript is focused on the followed methodology. In my opinion the author should analyze more the supershear rupture and the effects of the earthquake
Within the attached manuscript you will find my comments in detail
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Review of the manuscript:
Geometric Variation in the Surface Rupture of the 2018 Mw7.5 Palu Earthquake from Subpixel Optical Image Correlation
authors Li, Zhang, Shan, Zhao, Song
submitted for publication to Remote sensing
The authors calculate the coseismic horizontal displacement field originated by a Mw 7.5 earthquake occurred in Indonesia in 2018, and carry out a quantitative analysis of the geometric characteristics of the surface rupture produced by the event.
Review
I appreciate the manuscript, that from a general point of view is concise, to the point, and easy to read. The authors clearly state their intentions, describe the methods used, and present and discuss their results in a proper way. My opinion is that the paper is generally well written except for some typos and minor errors that can be easily resolved. Therefore, I think that the paper could deserve publication, provided that the authors make the minor changes that I describe in the following. All the suggestions, comments, and requests to the authors are provided also in the annotated pdf version of the manuscript. I have no major issues to raise, however there are some suggestions and comments that are listed here:
1) the quality of the figures is generally poor, figures 5, 6 and 7 in particular are too small and difficult to read. Most important, when a map is displayed in a figure it is mandatory in my opinion to show a graphic scale of the distance to help the reader understand the size of what he/she is watching. Figure 1 needs an inset showing the geographical location of the study area. Not all the subfigures are cited in the text.
2) I find some confusion in the estimates of the length of the rupture associated with the earthquake. In lines 115-116 a length of 75 km is reported, in lines 156 and 160 the surface rupture is 65 km-long. Also, it seems from figure 2 that the total extent of the rupture originated by the seismic event is about 150 km (this evidence is absent throughout the maintext), I think that a more clear phrasing is needed for this issue.
3) at the end of paragraph 4.2 it would be interesting to add a comparison between the characteristics and geometric variations that the authors infer for the 2018 event and those shown by the 1999 and 2001 earthquakes that are taken as recent examples of supershear events.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
This manuscript deals with the coseismic displacement field of the 2018 Palu earthquake from optical images. I found that data processing itself has been done carefully, and the obtained displacement field is persuasive. Unfortunately, however, this work lacks new insights brought from the obtained displacement field. Given that there have been many studies on the coseismic deformation field of the Palu earthquake by Socquet et al., among others, a new study needs to bring new insights. Although I acknowledge that the authors investigated the deformation field carefully, they did not bring any new scientific insights. If this paper were submitted right after the earthquake, it would have been published promptly. However, this paper would not be considered a publication if it is submitted now.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear authors,
After reading the revised manuscript I find it considerable improved and I am satisfied with your corrections
Reviewer 3 Report
I am please to see that the authors have done an excellent job in addressing my concern. I am not persuaded that this work is indeed original and worth being published. Therefore, I am happy to recommend immediate acceptance of this manuscript.
