Detecting DC Electrical Resistivity Changes in Seismic Active Areas: State-of-the-Art and Future Directions

Round 1

Reviewer 1 Report

This article is devoted to a review of articles on geoelectric monitoring carried out in China, Japan, the USA and Russia. The main tasks and problems which are associated with the possibility of using this method to predict earthquakes, are formulated clearly and logically. The drawings and diagrams, used by the author, correspond to the main content of the article and demonstrate the obtained results. At the same time, it is recommended to add information on geoelectric research, carried out at the Semipalatinsk Test Site in Kazakhstan, to section 3.5, devoted to the analysis of anthropic activities. For example, interesting results of regime measurements, which indicates ambiguous variations in the electrical resistivity of rocks due to technogenic changes in the fracturing of the massif, present in the article: Stromov, V.M.; Kabailov, A.N.; Drozdov A.V. Results of regime electric survey at Balapan Site, NNC RK Bulletin. 2005, 2, 95-100 (in Russian). It is also necessary to make technical corrections to the caption under Figure 5.

Author Response

Dear Reviewer,

I greatly appreciated your comments to improve the quality of the paper.

I have included in the section 3.5 the results obtained at the Balapan test site and corrected the caption of the Fig.5. Furthermore, the quality of some figures was improved and the paragraph "Discussion" was revised.

With best regards

Vincenzo Lapenna

Reviewer 2 Report

A critical review of the geoelectrical monitoring activities carried out in seismically active areas is presented and discussed in this paper. However, the quality of some figures is poor and needs to be improved.

1. The resolution of the Figure 2 is too low to see clearly, please modify it.

2. The text in the Figure 1 has low resolution and cannot be seen clearly, so it needs to be modified.

Author Response

Dear Reviewer,

I greatly appreciated your comments to improve the quality of the paper.

I have modified the figs 1 and 2 increasing the resolution. I have checked all the figures to increase their resolution. Furthermore, I have revised some sentences and the paragrah "Discussion".

With best regards

Vincenzo Lapenna

Reviewer 3 Report

The work "Detecting DC electrical resistivity changes in seismic active areas: state-of-the-art and future directions" by Vincenzo Lapenna reports a variety of tests concerning resistivity measurements compared to seismic activity. The theme is noteworthy and significant for the journal. However, a real discussion is missing in the text of this work, and conclusions seem not to be supported.

Specifically:

The introduction is characterized by citations that are few or not described at all. Results and information on methods need to be reported. Many figures are of very poor quality.

In Section Methods, descriptions of references are very poor, as are in Section Seismic Areas.

Lines 184–188 refer to ABMN and should be reported in a schematic figure where all the configurations of references appear so they can be cited. Schlumberger configuration is not reported.

Line 253 and the following, please, report all the distances between the epicenter and the different stations.

In lines 267-268, stress is not detected, it is hypothesized. Please, modify the sentence accordingly and describe a model that you used to deduce stress.

Line 286, it is not clear what the earthquake is.

Lines 302-303, are apparently contradictory.

Lines 333–335, there are missing details shown in the figure but not described.

Lines 395-396, very generic affirmation, please, explain better and why resistivity alone is not significant.

Line 502, please, report a detailed description of SP.

Line 509, the stress field is not measured, rewrite the sentence.

Lines 512-523, sentences concerning conclusions.

Line 531 and the following, it is not a discussion, there are no quantifications.

Line 566-570, all very speculative, not preceded by a true discussion, i) no references are reported, ii) and iii) very generic with no references and no discussion, iV) what statistical approaches do you suggest?

Line 590, the present work does not contain any retrospective analysis, and no technological limit has been analyzed and discussed.

Lines 600-613, it's a hope that ultimately says nothing precise.

Minor editing is needed:

line 108, technological;

line 137, CO_2;

line 234, >=>;

line 252, ofg;

line 265, ...be... .

Author Response

 Dear Reviewer,

I greatly appreciated your comments for improving the quality of the paper. I have considered point-to-point your comments and modified the text.

The work "Detecting DC electrical resistivity changes in seismic active areas: state-of-the-art and future directions" by Vincenzo Lapenna reports a variety of tests concerning resistivity measurements compared to seismic activity. The theme is noteworthy and significant for the journal. However, a real discussion is missing in the text of this work, and conclusions seem not to be supported.

The introduction is characterized by citations that are few or not described at all. Results and information on methods need to be reported. Many figures are of very poor quality.

In Section Methods, descriptions of references are very poor, as are in Section Seismic Areas.

I have improved the “Introduction” and “Methods” paragraphs paying great attention to describe all the references quoted in the text and to introduce more details in the description of the geoelectrical methodologies.   

The quality of the figures has been improved increasing the resolution.

The Paragraph “Discussion” has been completely revised introducing more critical and quantitative analyses. 

Lines 184–188 refer to ABMN and should be reported in a schematic figure where all the configurations of references appear so they can be cited. Schlumberger configuration is not reported.

More information on the geoelectrical arrays and a focus on the Schlumberger monitoring array were introduced in the revised version. Furthermore, a new figure has been added.

Line 253 and the following, please, report all the distances between the epicenter and the different stations.

We have better specified in the text the distances between the epicenters and the monitoring stations.

In lines 267-268, stress is not detected, it is hypothesized. Please, modify the sentence accordingly and describe a model that you used to deduce stress.

I have modified the sentence.

Line 286, it is not clear what the earthquake is.

I have better specified that the earthquake occulted in San Andrea fault south of the small town of Hollister.

Lines 302-303, are apparently contradictory.

I have rewritten the sentence.

Lines 333–335, there are missing details shown in the figure but not described.

More details about the data displayed in the figure have been added.  In particular, the temporal variability of the telluric signals has been discussed.

Lines 395-396, very generic affirmation, please, explain better and why resistivity alone is not significant.

I have specified the absence of information about the seismic source parameters and the hydrogeological data (e-g. permeability).

Line 502, please, report a detailed description of SP.

A short description of the Self-potential method has been introduced.

Line 509, the stress field is not measured, rewrite the sentence.

I have corrected the sentence.

Lines 512-523, sentences concerning conclusions.

I have moved these sentences in the paragraph “Conclusions”

Line 531 and the following, it is not a discussion, there are no quantifications.

Line 566-570, all very speculative, not preceded by a true discussion, i) no references are reported, ii) and iii) very generic with no references and no discussion, iV) what statistical approaches do you suggest?

Line 590, the present work does not contain any retrospective analysis, and no technological limit has been analyzed and discussed.

The paragraph “Discussion” has been largely modified according to the comments of the referee. I have added quantitative comments about statistical methods and a critical analysis of the technological limits.

Lines 600-613, it's a hope that ultimately says nothing precise.

I have completely rewritten this part. 

With best regards

Vincenzo Lapenna

Round 2

Reviewer 3 Report

The revised work Detecting DC electrical resistività changes in seismic active areas: state-of-the-art and future directions by Vincenzo Lapenna has been significante improved. It Is now at standard level to be published. Only a few points to be rewritten: Lines 112-115 of the introduction do not correspond to what has been reported in the text, as no quantitative calculus and discussion are reported It should be clearly written that It Is only a qualitative report of mentioned arguments at Lines 112-115 will be discussed. At the same way lines 118 and 119 do not report amy new approach o methods, they are simply prospected or required but not discussed, It Is necessari to clearly declare It.

A few corrections at lines:

178 A:

217 hidden??

248 only >=

576,580 interesting does no sense, please explain

636 ]

288,307,640,653 delete spaces

Author Response

Dear Reviewer,

I greatly appreciated your comments.

First of all, I have modified some sentences in the "Introduction" clarifying that a qualitative analysis has been performed and the novel approaches are only outlined. Furthermore, I have corrected some typewriting errors.

With best regards

Vincenzo Lapenna