Seismogenic Effects in Variation of the ULF/VLF Emission in a Complex Study of the Lithosphere–Ionosphere Coupling Before an M6.1 Earthquake in the Region of Northern Tien Shan

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript deals with an apparently well-designed observational study of potential precursors to a M6.1 earthquake in Kazakhstan, detected in ultra-low and very-low frequency electromagnetic emissions (ENPEMF), gamma-ray flux in a borehole, and Doppler frequency shifts (DFS) of ionospheric signals. The multi-parameter approach, including high-resolution temporal monitoring and well-calibrated instruments, allows for an investigation on the possible lithosphere-ionosphere coupling and seismogenic signal propagation. The close proximity of the observation points to the earthquake epicenter provides a rare opportunity for near-field validation.

My opinion is that the manuscript has some scientific merit and could make a valuable contribution to the field of earthquake precursors and seismo-electromagnetic phenomena. However, a major revision is needed before publication, in particular, a more robust statistical treatment, a longer interval of investigation and a clearer contextual framing are necessary.

 

Major Comments

1. Statistical rigor is missing: while the temporal correlation of anomalies is well presented, the study lacks formal statistical analysis to confirm the significance of the observed deviations. Introducing signal detection metrics (e.g., z-scores, confidence intervals, or hypothesis testing), based on past history or other considerations, would strengthen the argument and reduce potential confirmation bias.
2. Limitation  to a single event: the conclusions, although promising, are based on a single earthquake event. The authors are encouraged to either expand the dataset with historical cases or clearly frame the study as a case report with hypotheses for future validation. In addition, the search for a precursor is based on till about 30 days before the earthquake occurrence and 10 days after, that is really a too short interval of time to give a proclamation of a reliable earthquake precursor!
3. Mechanistic assumptions: the manuscript discusses gamma-ray flux reductions as due to changes in radon dynamics but offers no direct chemical or atmospheric measurements to support this. The inferred chain of causality (from lithosphere stress to ionospheric disturbance) is rather speculative and should be discussed more critically, including potential alternative explanations or unknowns.
4. Real-Time Detection Claim: the statement that the gamma anomaly "indicated an approaching earthquake with high probability" and was "detected in real time" requires clarification. If this is a retrospective conclusion, it should be stated clearly, but also justified. If real-time alerts were triggered, (but I do not think so!) details of thresholds or alerting mechanisms should be described.
5. Potential environmental influence of gamma flux. Please include weather data or mention whether precipitation or humidity could influence gamma flux readings.

Minor Comments

6. Title: I would indicate also the name of the earthquake or the region where it occurred. I suggest something like: “Seismogenic Effects in Variation of the ULF/VLF Emission at a Complex Study of the Lithosphere-Ionosphere Coupling before the 4 March, 2024 Kazakhstan M6.1 Earthquake”

7. Figures: Add error bars or statistical thresholds to figures showing ENPEMF, gamma-ray, and DFS variations to aid in visual interpretation. Figure 6 is the only one that provides something, although it is very rudimental (just the threshold of -1sigma).

8. Acronym ENPEMF defined in lines 27-38: it is not clear the reason of this acronym since the initials of the defining words do not coincide.

9. Reference consistency: A few references are repeated or incomplete, especially of websites (e.g. www.some.kz in line 567 is not found; do you mean www.sme.kz ?  and https://ccmc.gsfc.nasa.gov/ seems too general: could you provide a more specific link as you did with the link of ref. [40]?

10. Improve clarification for the sensor orientation significance (e.g., why N–S aligned antenna detected a signal and E–W did not): as I understand this is related to the orientation of the stations with respect to the epicentre, as shown in the right inset of figure 1. However, I would suggest to indicate the epicentre also in Figure 4.

11. Line 186. The word “from” is written two times consecutively.

12. Line 459. Please correct “lethosphere” with “lithosphere”..

 

Comments on the Quality of English Language

Please consider English language editing. Several grammatical and phrasing issues should be addressed: e.g., “obedient” in line 208,  and “an interest was excited …” (?) in line 95,  should be revised. Moreover, within the text, I counted 55 (!) times using the word “variation”. Please use other synonyms (e.g. change, trend, alteration, modification, etc.). Sometime it could be just removed: e.g. in line 436 you can just write “… detected in the time series of …”

Author Response

Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
Quality of English Language
(x) The English could be improved to more clearly express the research.
( ) The English is fine and does not require any improvement.
    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

This manuscript deals with an apparently well-designed observational study of potential precursors to a M6.1 earthquake in Kazakhstan, detected in ultra-low and very-low frequency electromagnetic emissions (ENPEMF), gamma-ray flux in a borehole, and Doppler frequency shifts (DFS) of ionospheric signals. The multi-parameter approach, including high-resolution temporal monitoring and well-calibrated instruments, allows for an investigation on the possible lithosphere-ionosphere coupling and seismogenic signal propagation. The close proximity of the observation points to the earthquake epicenter provides a rare opportunity for near-field validation.

My opinion is that the manuscript has some scientific merit and could make a valuable contribution to the field of earthquake precursors and seismo-electromagnetic phenomena. However, a major revision is needed before publication, in particular, a more robust statistical treatment, a longer interval of investigation and a clearer contextual framing are necessary.

 

Major Comments

    Statistical rigor is missing: while the temporal correlation of anomalies is well presented, the study lacks formal statistical analysis to confirm the significance of the observed deviations. Introducing signal detection metrics (e.g., z-scores, confidence intervals, or hypothesis testing), based on past history or other considerations, would strengthen the argument and reduce potential confirmation bias.

++++ ANSWER
Much thanks for your recommendation. A statistical analysis of the data  using the Student coefficient and the confidence check of the difference did confirm the significance and reliability of the effects revealed in the period of earthquake preparation.

As for the past history of our investigation, the examples of former experimental results are referenced to as Refs. [34], [36], [37], and discussed over the text of the present paper. The articles mentioned in the references contain the historical data of a simultaneous complex monitoring of the parameters of geophysical fields (in particular, on the gamma ray flux and on the Doppler shift of ionospheric signal) made within the Dobrovolsky region during short-time preparation period of several M4.2-M7.1 earthquakes.

 

    Limitation  to a single event: the conclusions, although promising, are based on a single earthquake event. The authors are encouraged to either expand the dataset with historical cases or clearly frame the study as a case report with hypotheses for future validation. In addition, the search for a precursor is based on till about 30 days before the earthquake occurrence and 10 days after, that is really a too short interval of time to give a proclamation of a reliable earthquake precursor!

++++ ANSWER
We took into account your remark concerning the "proclamation of a reliable earthquake precursor" and changed the statement "... mutually confirming precursors of the earthquake" in Section 3.7 to a more correct one "...  mutually confirming seismogenic anomalies preceding the earthquake".

Also, the final statement in the Conclusion section was correspondingly modified.

As for the remark concerning limitation with a single event. Our conclusions are based on the fact that during the time interval from February 1 to March 15 the anomalous effects before the earthquake were clearly, and almost simultaneously, seen in ENIEMF, gamma ray flux, and DFS. This is why we assume that this period of time is sufficient to consider the revealed anomalies as seismogenic and, presumably, propagating from the lithosphere up to the height of ionosphere. It was not supposed in the paper to consider these anomalies as a reliable precursor of an earthquake. Nevertheless, we believe that such investigations, even isolated ones, allow us to approach to understanding the processes in the geophysical fields which take place before major earthquake.

 

    Mechanistic assumptions: the manuscript discusses gamma-ray flux reductions as due to changes in radon dynamics but offers no direct chemical or atmospheric measurements to support this.

++++ ANSWER
Really, we did not conduct direct measurement of the dynamics of radon exhalation at a depth of 100m in the borehole, where the continuously operating gamma detector is installed. The measurement of radon content requires either lowering the radon-meter into the borehole, which is impossible in our conditions, or pumping the air out of there, which will inevitably change the air environment of the borehole.

Generally, for monitoring the variation of radon in a seismically active environment the devices are widely applied which are based on detection of the gamma radiation of the products of radon decay. Therefore, in our study we prefer using a scintillation gamma detector which ensure uninterruptable registration with high time resolution and without disturbing the natural air environment of the borehole.

 

    The inferred chain of causality (from lithosphere stress to ionospheric disturbance) is rather speculative and should be discussed more critically, including potential alternative explanations or unknowns.

++++ ANSWER
Presently, there is no unambiguous answer to the question on the casual relationship between the stress in the lithosphere and disturbance in the ionosphere. Nevertheless, many approaches do exist in modern literature for explanation of the transfer of seismogenic disturbances from the lithosphere up to the height of ionosphere. In the present paper we cite the Refs [23-25, 29-31, 49, 50], where the questions of lithosphere-atmosphere-ionosphere coupling are considered from the experimental and theoretical points of view. In particular, it is widely discussed the possible mechanism of lithosphere-ionosphere coupling, in which radon and daughter products of its decay are a primary ionization source of the near-surface atmosphere. The results of our study most closely  correspond to the concept of lithosphere-atmosphere-ionosphere coupling well described in [29-31], do not contradict to this concept, and, in our opinion, do not require alternative explanations.

 

    Real-Time Detection Claim: the statement that the gamma anomaly "indicated an approaching earthquake with high probability" and was "detected in real time" requires clarification. If this is a retrospective conclusion, it should be stated clearly, but also justified. If real-time alerts were triggered, (but I do not think so!) details of thresholds or alerting mechanisms should be described.

++++ ANSWER
A declaration that the gamma anomaly "indicated a high-risk earthquake" was indeed made at the Academic Council of our Institute (Institute of the Ionosphere) 4 days before the earthquake. It is that was a motivation for analyzing the monitoring data on ULF/VLF electromagnetic radiation and the data of the Doppler ionosonde. It should be noted that our activity has a research character, and we do not have any real-time announcement system, though we hope that this is a work for the future.

Up to the present time, we accumulated some positive experience, that practically at every noticeable earthquake (within the limits of Dobrovolsky radius) in the record of the gamma ray flux measured in the borehole a cove-like depression has appeared 2-10 days before the main shock. In Section 3.4 we mention this fact and cite Ref. [37] to the analogous, just published, data.

 

    Potential environmental influence of gamma flux. Please include weather data or mention whether precipitation or humidity could influence gamma flux readings.

++++ ANSWER
The data concerning the influence of weather conditions (such as rain, hail, snow, and temperature variation) on the intensity of gamma ray flux measured in the near-earth atmosphere and borehole are considered in detail in Refs. [37, 41], and also explained over the text of the article.

 

 

Minor Comments

6. Title: I would indicate also the name of the earthquake or the region where it occurred. I suggest something like: “Seismogenic Effects in Variation of the ULF/VLF Emission at a Complex Study of the Lithosphere-Ionosphere Coupling before the 4 March, 2024 Kazakhstan M6.1 Earthquake”

++++ ANSWER
We took into account your advise and changed the title to "Seismogenic effects in variation of the ULF/VLF emission at a complex study of the lithosphere-ionosphere coupling before a $M6.1$~earthquake in the Northern Tien Shan region".

 

7. Figures: Add error bars or statistical thresholds to figures showing ENPEMF, gamma-ray, and DFS variations to aid in visual interpretation. Figure 6 is the only one that provides something, although it is very rudimental (just the threshold of -1sigma).

++++ ANSWER
We think that using traditional error bars would fairly encumber the plots presented in the paper because of a big number of separate data points generally indicated in them. So, only the one-sigma standard deviation levels were indicated with straight lines in Figures 6 and 10, when they are really  useful for discussion of the reliability of conclusions made on the basis of the gamma ray flux and Doppler shift data.

As for the anomalous effects detected in the variation of electromagnetic fields and presented in Figures 2 and 7, the amplitude of these effects is many times above the background level (seemingly, due to close location of the registering equipment to the epicenter of the earthquake), so indication of explicit error bars may be avoided there.

 

8. Acronym ENPEMF defined in lines 27-38: it is not clear the reason of this acronym since the initials of the defining words do not coincide.

++++ ANSWER
The sequence of the words before the definition of this abbreviation in the article's text was changed to correspond to the order of letters in the term.

 

9. Reference consistency: A few references are repeated or incomplete, especially of websites (e.g. www.some.kz in line 567 is not found; do you mean www.sme.kz ?  and https://ccmc.gsfc.nasa.gov/ seems too general: could you provide a more specific link as you did with the link of ref. [40]?

++++ ANSWER
The site "www.some.kz" is presently closed for reconstruction.

The reference "https://ccmc.gsfc.nasa.gov" was changed to a more specific one "https://kauai.ccmc.gsfc.nasa.gov/instantrun/iri/".

 

10. Improve clarification for the sensor orientation significance (e.g., why N–S aligned antenna detected a signal and E–W did not): as I understand this is related to the orientation of the stations with respect to the epicentre, as shown in the right inset of figure 1. However, I would suggest to indicate the epicentre also in Figure 4.

++++ ANSWERS
The ferrite antennas of the MGR-02-16 registration device have some radiation pattern, such that the antenna oriented along the "North-South" line has a good sensitivity to the signals propagating in that direction, but is badly sensitive in the direction "East-West", and vise verse.

At the earthquake on 4 March 2024 the radiation pattern of the "North-South" antenna happened to be pointing to the epicenter. We assume that this coincidence did assure favorable conditions for acceptance of the electromagnetic signals from the side of the earthquake epicenter.

Also, the epicenter of the earthquake was located 30km apart from the Almaty city. The scale of the map in Figure 4 is too small to show the epicenter point separately, since it would coincide with the designation of Almaty.

 

11. Line 186. The word “from” is written two times consecutively.

12. Line 459. Please correct “lethosphere” with “lithosphere”..

++++ ANSWERS
Both misspellings were fixed.

 

Comments on the Quality of English Language

Please consider English language editing. Several grammatical and phrasing issues should be addressed: e.g., “obedient” in line 208,  and “an interest was excited …” (?) in line 95,  should be revised. Moreover, within the text, I counted 55 (!) times using the word “variation”. Please use other synonyms (e.g. change, trend, alteration, modification, etc.). Sometime it could be just removed: e.g. in line 436 you can just write “… detected in the time series of …”

++++ ANSWER
The whole text of the article was strictly verified once more and corrected when needed.

Submission Date
25 March 2025
Date of this review
09 Apr 2025 14:37:08

 

Reviewer 2 Report

Comments and Suggestions for Authors

The Authors analyze time evolutions of parameters related to the Earth's natural pulsed electromagnetic field in VLF and ULF domains, gamma ray flux, and ionospheric variations in period around a M6.1 Earthquake which has occurred on 4 March 2024. The results of the study indicated potential precursors of the earthquake and the role of the medium ionization in propagation of seismogenic disturbances as a channel for realization of the lithosphere-ionosphere coupling.

My opinion is that the manuscript is well written and should be accepted for publication after minor revision.

REMARKS:

1. The authors should clearly define what pulses of the electromagnetic field are, ie. what are the criteria to detect it.

2. Figure 2: X axis - it is unusual for 5.5 days to be the interval marked on the axis. 5 or 7 (weeks) would be much better. Thus, only dates could be given. Similarly for Figures 3, 5, 6.

3. What is the time resolution of the points shown on the graphs and how exactly were the displayed values obtained (are they averaged pps values in some interval or something else)? Similarly for Figures 3, 5, 6.

Author Response

Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
Quality of English Language
( ) The English could be improved to more clearly express the research.
(x) The English is fine and does not require any improvement.
    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

The Authors analyze time evolutions of parameters related to the Earth's natural pulsed electromagnetic field in VLF and ULF domains, gamma ray flux, and ionospheric variations in period around a M6.1 Earthquake which has occurred on 4 March 2024. The results of the study indicated potential precursors of the earthquake and the role of the medium ionization in propagation of seismogenic disturbances as a channel for realization of the lithosphere-ionosphere coupling.

My opinion is that the manuscript is well written and should be accepted for publication after minor revision.

REMARKS:

1. The authors should clearly define what pulses of the electromagnetic field are, ie. what are the criteria to detect it.

++++ ANSWER
The possibility of electromagnetic pulses appearance in the Earth's crust as a result of conversion on the tectonic energy into electric one was pointed in 1970s by A.A.Vorobyov. He assumed that a rise in intensity of the ENPEMF pulses may be observed both at the time and before an earthquake.
[Vorobyov, A. A. On the probability of electric discharges in the Earth’s interior (in Russian). Geologiya i Geophysika 1970, 12, 3–13. 482;
Vorobyov, A. A. Tektoelectric phenomena and appearance of the natural pulsed electromagnetic field inside the bowels of the Earth (in Russian); EIEMPZ Tomsk TPU, 1979; p. 582].

The nature of these pulses is connected with the generation and relaxation processes of electric charge on the plane of destruction at stress-strained state of rock. The sources of natural electromagnetic field in rock may be inhomogeneities of the ground structure, non-uniformity of the strained pattern, fissures and micro-fissures. All these sources generate the pulsed electromagnetic field due to conversion into electricity of the mechanic energy of deformation waves in the Earth's mantle, tides, microseisms, winds, and technogenic load, creating the natural electromagnetic background of lithospheric origin.
[Hao, G.; Bai, Y.; Zhao, J.; Wu, M.; Yang, Y. A receiving instrument of the Earth’s natural pulse electromagnetic field and its
data analysis via time-frequency method before an earthquake. In Proceedings of the IEEE International Instrumentation and
Measurement Technology Conference (I2MTC). 2017; pp. 1–6.
doi:10.1109/I2MTC.2017.7969654;
Malyshkov, S. Y.; Gordeev, V. F.; Polivach, V. I.; Shtalin, S. G.; Pustovalov, K. N. Estimation of the lithospheric component share in the Earth natural pulsed electromagnetic field structure. IOP Conf. Series: Materials Science and Engineering 2017, 189, 012023.
doi:10.1088/1757-899X/189/1/012023.]

Answering your question on the detection criteria of the anomalous ENPEMF pulses at earthquake preparation we can allude to the experimental investigations
[V.F. Gordeev, S.Yu. Malyshkov, S.G. Shtalin, V.I. Polivach and V.A. Krutikov. Detection of geodynamic activity areas based on the Earth's electromagnetic noise parameters. IOP Conf. Series: Earth and Environmental Science 48 (2016) 012026
doi:10.1088/1755-1315/48/1/012026;
Gordeev, V.; Malyshkov, S.; Polivach, V.; Shtalin, S., Earth’s natural pulsed electromagnetic field (ENPEMF) temporal variation anomalies as earthquake precursors. In: Trigger effects in geosystems. 2019; pp.
53–61
doi:10.1007/978-3-030-31970-0_6.2019].

In these works the variation of the Earth's natural pulsed electromagnetic field (ENPEMF) is considered as a consequence of dynamoelectric conversion in a solid body of fault structure, which reveals as a radio-signal in the VLF range (3-30kHz). Also, the registration possibility is demonstrated of the anomalous ENPEMF variation caused by upcoming earthquake at an up to 500km distance. For the purpose, a network of synchronously operating, spatially distributed registration stations of electromagnetic signal is used, which are applicable for the short-term earthquake forecast. The authors stress especially, that, in contrast with distant signals, the local responses mainly traverse rocks, and may be registered in immediate vicinity from an earthquake epicenter.

Thus, the basic criterion for identification the anomalous ENPEMF pulses in our investigation was a very close location of the ENPEMF registration equipment from the epicenter of the earthquake, only at a 12.2km distance. This is why two days before the earthquake we were able to detect a distinct burst in ENPEMF intensity essentially prevailing the background. Also, a suppression of the usual diurnal rhythm of ENPEMF variation was observed 13 days before the main shock, as an evidence on the effect of lithospheric processes preceding the earthquake.

 

2. Figure 2: X axis - it is unusual for 5.5 days to be the interval marked on the axis. 5 or 7 (weeks) would be much better. Thus, only dates could be given. Similarly for Figures 3, 5, 6.

++++ ANSWER
The plots in all mentioned figures were redrawn with setting more convenient labels along their time axes.

 

3. What is the time resolution of the points shown on the graphs and how exactly were the displayed values obtained (are they averaged pps values in some interval or something else)? Similarly for Figures 3, 5, 6.

++++ ANSWERS

Figure 2:
"The accumulation time of the \EPZ\ pulse signals for each point in this plot equals to 5\,min; in the figure these data are presented in normalization to the amount of pulses arrived in one second (p.p.s.).". This explanation was added into Section 3.2.

Figure 3:
The data on geomagnetic conditions in February-March 2024 were taken `as is` at the site "https://wdc.kugi.kyoto-u.ac.jp", a reference to which is mentioned in the text. The time resolution of these time series is 3h.

Figure 5:
The data on ENPEMF intensity measured at the Kireyevsk and Sarapul stations for this figure were obtained with a 1h time resolution. This remark was added to the text.

Figure 6:
"In the measurement, the output pulse signals coming from the gamma-detector were continuously counted during succeeding 10\,s long time intervals, then the momentary counting rate was defined as an amount of the pulses arrived per one second (p.p.s.)". This explanation was added into Section 3.4.

 

Submission Date
25 March 2025
Date of this review
15 Apr 2025 21:20:15

 

Reviewer 3 Report

Comments and Suggestions for Authors

The authors use the variation of ULF/VLF Emission to study the lithosphere-Ionosphere coupling before a M6.1 earthquake. A few minor points require revision before the paper can be accepted for publication.

1. In Figure 3, the image with a black background needs to be redrawn.

2. How to distinguish changes caused by geomagnetic storms?

3. The distance affected is approximately ρ=10^(0.43M)=420 km. In Figure 4, the distance from the Sarapul and Kireyevsk to the epicenter equals correspondingly 2224 km and 1573 km. This is too far. How can we identify his relevance?

Author Response

Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
Quality of English Language
( ) The English could be improved to more clearly express the research.
(x) The English is fine and does not require any improvement.
    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

The authors use the variation of ULF/VLF Emission to study the lithosphere-Ionosphere coupling before a M6.1 earthquake. A few minor points require revision before the paper can be accepted for publication.

1. In Figure 3, the image with a black background needs to be redrawn.

++++ ANSWER
The plot in this figure was redrawn with better quality.

 

2. How to distinguish changes caused by geomagnetic storms?

++++ ANSWER
This question is dealt with in the discussion of Figure 3 (see the paragraph started 'It is important to note...' in Section 3.2. As follows from the plots of this figure, during 1 February - 3 March 2024 the geomagnetic conditions remained quite, and only on 3 February a weak geomagnetic storm occurred. As seen in Figures 2 and 11, suppression of the diurnal rhythm of ENPEMF took place in the time of quite geomagnetic field, and the burst in intensity of ENPEMF on 2 March occurred more then one day before the beginning of the storm.

 

3. The distance affected is approximately ρ=10^(0.43M)=420 km. In Figure 4, the distance from the Sarapul and Kireyevsk to the epicenter equals correspondingly 2224 km and 1573 km. This is too far. How can we identify his relevance?

++++ ANSWER
You are right in saying that any effect of the earthquake preparation could hardly be awaited to be seen at the distances of 2224 km and 1573 km. But, according to Figure 5, we may conclude, that the weak geomagnetic storm on 3 March did not influence the ENPEMF variations independently on location of the registration point. This gives us a ground to conclude that it is the earthquake preparation process that the anomalous effects in ENPEMF variation detected near epicenter are connected with, but not the geomagnetic storm.

Thus, with account to the global influence of geomagnetic storms on various geophysical processes, we compare the ENPEMF monitoring results obtained both in vicinity to the epicenter and at larger distances. It is important, that in all points the monitoring was made with the devices of a same type, i.e. MGR-02-16. As follows from Figure 5, the weak geomagnetic storm happened on 3 March had no effect on the ENPEMF variation.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I am satisfied by the revision. Thanks

Author Response

Much thanks for your review, useful remarks, and suggestions.