Possible Interrelations of Space Weather and Seismic Activity: An Implication for Earthquake Forecast

Round 1

Reviewer 1 Report

The paper reports a study on the possible connection between solar flares and seismic activity. The study is conducted for the period 1997-2023. Using a method of epoch superposition, it is shown that an increase of seismicity is observed especially in the region around the subsolar point (up to 38%) during 10 days after the solar flares. In particular considering the aftershock sequence of M=9.1 earthquake (Sumatra-Andaman Islands, December 26, 2004) it is revealed that from 7 days after the solar flare of January 20, 2005 the number of aftershocks with M≥2.5 increases more than 20 times. Another main result is related to the aftershocks sequence of the M=7.1 Darfield earthquake (New Zealand, September 4, 2010,) where 6 days after solar flares two strong aftershocks (M>6) occurred. So, the possibility that solar flares could trigger earthquakes is proposed. In particular for the triggering of earthquakes a model of natural electro-magnetic mechanism is discussed and proposed for a short-term earthquake prediction.

 REMARKS

At first, I wish to precise that earthquakes are a natural phenomenon and in nature no prediction exists. So, we must speak of forecast not of prediction.

The forecast of an earthquake (in order to save life) implies:

a) to indicate the position of the epicenter within a circle of diameter 20-30Km,

b) to indicate the occurrence time within 10 days as maximum,

c) to indicate the M (Richter) as ≥ a value. Generally, a value of 6.0 seems reasonable.

The probability of success must be greater than 80% or so on. According to the most recent results obtained in the world, some forecast could be possible only using several different parameters characterized by different precursory times. The Authors describe a method to use only the occurrence of solar flares for making a forecast. I do not agree on this topic; really, the occurrence of solar flares as triggering of earthquakes presented in this paper is useful only to better define the occurrence time (previous point b) and it is a short-term precursor. My opinion is that external effects as solar flares, geomagnetic storms, planetary alignment…….. can trigger strong earthquakes in the world. Different possible mechanisms of the triggering have been proposed and developed. The present paper proposes a natural electromagnetic mechanism and it seems to me reasonable.

According to my opinion, the results presented in the present paper are interesting and should be disclosed.

My main remark to the Authors is to take into account the previous considerations in order to make some modification and improvement in the text.

 MINOR REMARKS

·       Change the word “prediction” in “forecast”;

·       I suppose that the magnitude M values reported in the text are the Richter values. Actually, the Mw (moment magnitude) is generally used and the values Mw are 0.2-03 greater than the M ones. Probably, a specification could be added in the text the first time the magnitude is mentioned;

·       Sometimes in the text is written M(a value) earthquake, (as an example pag. 8 line 2, M9.1); correct is M=a value, in the example M=9.1;

·       Some lines should be added in the text to clarify the meaning of “solar flares of X-class” and probably the indications as “X7.2 class” should be modified

The paper reports a study on the possible connection between solar flares and seismic activity. The study is conducted for the period 1997-2023. Using a method of epoch superposition, it is shown that an increase of seismicity is observed especially in the region around the subsolar point (up to 38%) during 10 days after the solar flares. In particular considering the aftershock sequence of M=9.1 earthquake (Sumatra-Andaman Islands, December 26, 2004) it is revealed that from 7 days after the solar flare of January 20, 2005 the number of aftershocks with M≥2.5 increases more than 20 times. Another main result is related to the aftershocks sequence of the M=7.1 Darfield earthquake (New Zealand, September 4, 2010,) where 6 days after solar flares two strong aftershocks (M>6) occurred. So, the possibility that solar flares could trigger earthquakes is proposed. In particular for the triggering of earthquakes a model of natural electro-magnetic mechanism is discussed and proposed for a short-term earthquake prediction.

REMARKS

At first, I wish to precise that earthquakes are a natural phenomenon and in nature no prediction exists. So, we must speak of forecast not of prediction.

The forecast of an earthquake (in order to save life) implies:

a) to indicate the position of the epicenter within a circle of diameter 20-30Km,

b) to indicate the occurrence time within 10 days as maximum,

c) to indicate the M (Richter) as ≥ a value. Generally, a value of 6.0 seems reasonable.

The probability of success must be greater than 80% or so on. According to the most recent results obtained in the world, some forecast could be possible only using several different parameters characterized by different precursory times. The Authors describe a method to use only the occurrence of solar flares for making a forecast. I do not agree on this topic; really, the occurrence of solar flares as triggering of earthquakes presented in this paper is useful only to better define the occurrence time (previous point b) and it is a short-term precursor. My opinion is that external effects as solar flares, geomagnetic storms, planetary alignment…….. can trigger strong earthquakes in the world. Different possible mechanisms of the triggering have been proposed and developed. The present paper proposes a natural electromagnetic mechanism and it seems to me reasonable.

According to my opinion, the results presented in the present paper are interesting and should be disclosed.

My main remark to the Authors is to take into account the previous considerations in order to make some modification and improvement in the text.

MINOR REMARKS

·      Change the word “prediction” in “forecast”;

·   I suppose that the magnitude M values reported in the text are the Richter values. Actually, the Mw (moment magnitude) is generally used and the values Mw are 0.2-03 greater than the M ones. Probably, a specification could be added in the text the first time the magnitude is mentioned;

·      Sometimes in the text is written M(a value) earthquake, (as an example pag. 8 line 2, M9.1); correct is M=a value, in the example M=9.1; 

S  Some lines should be added in the text to clarify the meaning of “solar flares of X-class” and probably the indications as “X7.2 class” should be modified.

Author Response

Please, see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Please find the report in the attachment!

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I have read the new version of the paper and I have seen that my suggestions have been considered. So, for me it is okay!

Author Response

All comments and suggestions from Reviewer 1 were taken into account and appropriate corrections were made. Thanks for your support.