the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
On the set of deterministic phenomena preceding the earthquake June 25, 2021 with a magnitude of 5.4 near the city of Yayladere (Turkey)
Lev P. Kogan
Konstantin H. Kanonidi
Igor Bubukin
Valeria B. Shtenberg
Larisa N. Volvach
Abstract. The article examines the 5.4 magnitude earthquake that occurred on June 25, 2021 in the vicinity of Yayladere (Turkey). The analysis of the geomagnetic measurements carried out revealed a set of deterministic processes that preceded this event and are interpreted as its precursors. An estimate is made of the average time between the interval of existence of such phenomena and the moment of the earthquake under consideration. As a result, close values of the corresponding averaged time intervals were obtained for the statistics of all three components of the geomagnetic field considered in the article. The proposed technique can be used to predict seismic processes in various regions of the world in a near real-time mode.
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Alexandr Volvach et al.
Interactive discussion
Status: closed
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RC1: 'Comment on angeo-2023-7', Anonymous Referee #1, 19 May 2023
In this manuscript the authors proposed a technique that can be used to predict seismic events, based on the analysis of geomagnetic measurements. They tested the proposed technique on the 5.4 magnitude earthquake occurred on June 25, 2021 in Turkey. This is a hot topic in the last few decades and several works in recent years have tried to find possible seismic precursors through the analysis of electromagnetic field in the circumterrestrial environment.
However, without major revisions, this work cannot be considered for publication.
The authors should focus on the following points:
- They affirmed that the analysis of the geomagnetic measurements revealed a set of deterministic processes that preceded the seismic event and they are interpreted as its precursors. However, the authors had never shown that these processes do not appear in intervals of time far away from the earthquake.
- Lines 34-35: “the proposed approach made it possible to detect a number of phenomena that indicate a high probability of an imminent seismic event of significant magnitude”. This probability is not calculated, neither there is a link with the magnitude of the earthquake.
- What is the IAGA code of the magnetic observatory situated in Katsiveli? I couldn't find it on intermagnet.org
- Why the analysis on the geomagnetic observations doesn’t consider the solar forcing? Magnetic field variation arises from current systems caused by solar radiation changes. Other irregular current systems produce magnetic field changes caused by the interaction of the solar wind with the magnetosphere, leading to the so-called solar wind-magnetosphere coupling. Geomagnetic data are influenced by external forcing, how can you justify the link with the earthquake without considering the external forcing at all?
- In table 1, the values of intervals from the time of realization of «graphic precursors» to the moment of the beginning of the earthquake are reported, and they are different for each component of the field. However, the authors showed that the average on 6 hours is similar. However, what is the reason and the meaning of this average? Why it should be of some importance? Furthermore, how can be justified that these “graphic precursors” appear at different times and in different number on the 3 components of the geomagnetic field?
- The comparison with the Borok magnetometer data for the Z-component is not so good. Following the authors criteria, the 6 hours average of intervals from the time of realization of «graphic precursors» to the moment of the beginning of the earthquake is equal to 102 which is not similar to the value of the corresponding component at the Katsiveli test site (246).
There are also minor comments:
- Line 97: Typo: he and not The
- Lines 100-101: Why the duration of the channel existence must be at least 150 minutes? This and other constraints (for example the one at line 120) are not clear.
- Line 111: Maybe there are some typos otherwise the sentence is not clear.
- Line 147-148: Please justify the sentence: “The fact of the existence of such channels can be interpreted as the emergence of a set of deterministic processes immediately before an earthquake.”
- Line 152-153: Please justify the sentence: “Therefore, we will consider the moment of the indicated fifth testing as the time of realization of one of the types of "graphic precursors" of an impending earthquake”.
- Lines 184-185: the verb is missing in this sentence.
- Line 188: Here a word not in English appears.
Citation: https://doi.org/10.5194/angeo-2023-7-RC1 - AC1: 'Reply on RC1', Alexandr Volvach, 30 Jun 2023
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AC3: 'Reply on RC1', Alexandr Volvach, 30 Jun 2023
The comment was uploaded in the form of a supplement: https://angeo.copernicus.org/preprints/angeo-2023-7/angeo-2023-7-AC3-supplement.pdf
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AC4: 'Reply on RC1', Alexandr Volvach, 30 Jun 2023
The comment was uploaded in the form of a supplement: https://angeo.copernicus.org/preprints/angeo-2023-7/angeo-2023-7-AC4-supplement.pdf
-
RC2: 'Comment on angeo-2023-7', Anonymous Referee #2, 24 May 2023
The paper by Volvach and collaborators concerns the discovery of a deterministic precursor for the earthquake of Yayladere in 2021, using geomagnetic field measurements taken at two ground stations. The authors conclude that the proposed method can be used to forecast seismic events in the world.
The work presents serious weaknesses and I believe it is far from being ready for publication. I regret to recomend the work to be rejected based on the following comments and concerns.
1) The authors base the discovery and characterization of such precursor on one event ONLY. This preclude any statistical analysis in support to such discovery, as it would require the study of a relevant dataset of eartquake related geomagnetic data.
2) Without a proper statistically relevant sample, how can the authors possibly say that what they found is a deterministic process, related to the earthquake?
3) The explanation of the mathematical apparatus (see Eq. (2)) is highly convoluted and lacks of connection with the physics of the problem. This part should be improved. The choice of values and the meaning of the various indices is hindered in the text.
Looking at the last statement of section 2, the functional in Eq. 2 should be equivalent to the Shannon entropy of the sample. But the increase in the entropy of a time-sampled signal can be due also to other effects than the appearance of an independent stochastic term. Entropy can increase also if a very energetic not independent signal appears.4) The choice of the various values in Eq. 2 is not justified by the authors. What would happen if we had to apply the method to other earthquakes in other parts of the World?
5)The explanation of the data analysis and results (e.g. explanation of Fig 1 based on Eq. 4) is highly convoluted and really not clear. It is very difficult to understand the causal connection in L(n) from the plots, and the explanation of section 3 doesn't help. Everything is based on adjustable parameters which are never explained. Did not get the definition of small-scale vs. large-scale fluctuations. This may be done with a multiscale analysis or with a study of the increments of L(n), since here authors refer to increments of L. Why then not looking at the derivative of L(n)?
6) The manuscript is full of "random numbers". Why must a channel satisfy condition (5) with a value of 1.5 degrees? Why must a channel exist for at least 150 mins?
7) a series of obscure rules and constraints are listed to select geometric entities in the cartesian plane hosting L(n). An explanation for the choice of each of these rules (together with an improvement in clarity and organization of the manuscript) should be given.8) The search for precursors looks like a quest. After the big castle of obscure rules has been built, the quest starts. A question arises. How does L(n) look like in quiet days? How does it look like for other stations around the world?
9) There is no single statistical test to backup the authors' findings, and the whole analysis is based on one event! With no comparison with quiet data is not possible to derive the hint of the existence of a precursor, without even mentioning the need for a statistically relevant sample.
To summarize, the graphic identification of the precursor is made based entirely on what seems to be an aleatory collection of rules with no scientific/mathematical support.
There is no statistical test or analysis carried out to assess whether this is an actual precursor for earthquakes.Citation: https://doi.org/10.5194/angeo-2023-7-RC2 - AC2: 'Reply on RC2', Alexandr Volvach, 30 Jun 2023
-
AC5: 'Reply on RC2', Alexandr Volvach, 30 Jun 2023
The comment was uploaded in the form of a supplement: https://angeo.copernicus.org/preprints/angeo-2023-7/angeo-2023-7-AC5-supplement.pdf
Interactive discussion
Status: closed
-
RC1: 'Comment on angeo-2023-7', Anonymous Referee #1, 19 May 2023
In this manuscript the authors proposed a technique that can be used to predict seismic events, based on the analysis of geomagnetic measurements. They tested the proposed technique on the 5.4 magnitude earthquake occurred on June 25, 2021 in Turkey. This is a hot topic in the last few decades and several works in recent years have tried to find possible seismic precursors through the analysis of electromagnetic field in the circumterrestrial environment.
However, without major revisions, this work cannot be considered for publication.
The authors should focus on the following points:
- They affirmed that the analysis of the geomagnetic measurements revealed a set of deterministic processes that preceded the seismic event and they are interpreted as its precursors. However, the authors had never shown that these processes do not appear in intervals of time far away from the earthquake.
- Lines 34-35: “the proposed approach made it possible to detect a number of phenomena that indicate a high probability of an imminent seismic event of significant magnitude”. This probability is not calculated, neither there is a link with the magnitude of the earthquake.
- What is the IAGA code of the magnetic observatory situated in Katsiveli? I couldn't find it on intermagnet.org
- Why the analysis on the geomagnetic observations doesn’t consider the solar forcing? Magnetic field variation arises from current systems caused by solar radiation changes. Other irregular current systems produce magnetic field changes caused by the interaction of the solar wind with the magnetosphere, leading to the so-called solar wind-magnetosphere coupling. Geomagnetic data are influenced by external forcing, how can you justify the link with the earthquake without considering the external forcing at all?
- In table 1, the values of intervals from the time of realization of «graphic precursors» to the moment of the beginning of the earthquake are reported, and they are different for each component of the field. However, the authors showed that the average on 6 hours is similar. However, what is the reason and the meaning of this average? Why it should be of some importance? Furthermore, how can be justified that these “graphic precursors” appear at different times and in different number on the 3 components of the geomagnetic field?
- The comparison with the Borok magnetometer data for the Z-component is not so good. Following the authors criteria, the 6 hours average of intervals from the time of realization of «graphic precursors» to the moment of the beginning of the earthquake is equal to 102 which is not similar to the value of the corresponding component at the Katsiveli test site (246).
There are also minor comments:
- Line 97: Typo: he and not The
- Lines 100-101: Why the duration of the channel existence must be at least 150 minutes? This and other constraints (for example the one at line 120) are not clear.
- Line 111: Maybe there are some typos otherwise the sentence is not clear.
- Line 147-148: Please justify the sentence: “The fact of the existence of such channels can be interpreted as the emergence of a set of deterministic processes immediately before an earthquake.”
- Line 152-153: Please justify the sentence: “Therefore, we will consider the moment of the indicated fifth testing as the time of realization of one of the types of "graphic precursors" of an impending earthquake”.
- Lines 184-185: the verb is missing in this sentence.
- Line 188: Here a word not in English appears.
Citation: https://doi.org/10.5194/angeo-2023-7-RC1 - AC1: 'Reply on RC1', Alexandr Volvach, 30 Jun 2023
-
AC3: 'Reply on RC1', Alexandr Volvach, 30 Jun 2023
The comment was uploaded in the form of a supplement: https://angeo.copernicus.org/preprints/angeo-2023-7/angeo-2023-7-AC3-supplement.pdf
-
AC4: 'Reply on RC1', Alexandr Volvach, 30 Jun 2023
The comment was uploaded in the form of a supplement: https://angeo.copernicus.org/preprints/angeo-2023-7/angeo-2023-7-AC4-supplement.pdf
-
RC2: 'Comment on angeo-2023-7', Anonymous Referee #2, 24 May 2023
The paper by Volvach and collaborators concerns the discovery of a deterministic precursor for the earthquake of Yayladere in 2021, using geomagnetic field measurements taken at two ground stations. The authors conclude that the proposed method can be used to forecast seismic events in the world.
The work presents serious weaknesses and I believe it is far from being ready for publication. I regret to recomend the work to be rejected based on the following comments and concerns.
1) The authors base the discovery and characterization of such precursor on one event ONLY. This preclude any statistical analysis in support to such discovery, as it would require the study of a relevant dataset of eartquake related geomagnetic data.
2) Without a proper statistically relevant sample, how can the authors possibly say that what they found is a deterministic process, related to the earthquake?
3) The explanation of the mathematical apparatus (see Eq. (2)) is highly convoluted and lacks of connection with the physics of the problem. This part should be improved. The choice of values and the meaning of the various indices is hindered in the text.
Looking at the last statement of section 2, the functional in Eq. 2 should be equivalent to the Shannon entropy of the sample. But the increase in the entropy of a time-sampled signal can be due also to other effects than the appearance of an independent stochastic term. Entropy can increase also if a very energetic not independent signal appears.4) The choice of the various values in Eq. 2 is not justified by the authors. What would happen if we had to apply the method to other earthquakes in other parts of the World?
5)The explanation of the data analysis and results (e.g. explanation of Fig 1 based on Eq. 4) is highly convoluted and really not clear. It is very difficult to understand the causal connection in L(n) from the plots, and the explanation of section 3 doesn't help. Everything is based on adjustable parameters which are never explained. Did not get the definition of small-scale vs. large-scale fluctuations. This may be done with a multiscale analysis or with a study of the increments of L(n), since here authors refer to increments of L. Why then not looking at the derivative of L(n)?
6) The manuscript is full of "random numbers". Why must a channel satisfy condition (5) with a value of 1.5 degrees? Why must a channel exist for at least 150 mins?
7) a series of obscure rules and constraints are listed to select geometric entities in the cartesian plane hosting L(n). An explanation for the choice of each of these rules (together with an improvement in clarity and organization of the manuscript) should be given.8) The search for precursors looks like a quest. After the big castle of obscure rules has been built, the quest starts. A question arises. How does L(n) look like in quiet days? How does it look like for other stations around the world?
9) There is no single statistical test to backup the authors' findings, and the whole analysis is based on one event! With no comparison with quiet data is not possible to derive the hint of the existence of a precursor, without even mentioning the need for a statistically relevant sample.
To summarize, the graphic identification of the precursor is made based entirely on what seems to be an aleatory collection of rules with no scientific/mathematical support.
There is no statistical test or analysis carried out to assess whether this is an actual precursor for earthquakes.Citation: https://doi.org/10.5194/angeo-2023-7-RC2 - AC2: 'Reply on RC2', Alexandr Volvach, 30 Jun 2023
-
AC5: 'Reply on RC2', Alexandr Volvach, 30 Jun 2023
The comment was uploaded in the form of a supplement: https://angeo.copernicus.org/preprints/angeo-2023-7/angeo-2023-7-AC5-supplement.pdf
Alexandr Volvach et al.
Alexandr Volvach et al.
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