Geochemical and Fluid-Related Precursors of Earthquakes

2018 ◽  
pp. 219-228
Author(s):  
Giovanni Martinelli ◽  
Andrea Dadomo
Keyword(s):  
Precursors Of Earthquakes

Ionospheric precursors of earthquakes from satellites

2021 ◽  
Author(s):  
Angelo De Santis ◽  
Saioa A. Campuzano ◽  
Gianfranco Cianchini ◽  
Domenico Di Mauro ◽  
Dedalo Marchetti ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Random Distribution ◽  
Earthquake Magnitude ◽  
Quiet Time ◽  
Earthquake Forecast ◽  
Simple Scheme ◽  
Precursors Of Earthquakes ◽  
Space Distance ◽  
Space Approach

<p>In-situ magnetic field and electron density, as observed by Swarm and CSES satellites, are analyzed to identify possible anomalies in geomagnetic quiet time with respect to the ionospheric background. To avoid detecting possible anomalies induced by auroral activity we investigate regions between +50 and -50 degrees in magnetic latitude. Then a superposed epoch and space approach is applied to this anomaly dataset with respect to their time and space distance from shallow M5.5+ earthquakes occurred in about last 6 years. A comparison with analogous homogeneous random distribution of anomalies shows that the real anomaly concentrations found before the occurrence of earthquakes are statistically significant. In addition, we find that, in general, the anticipation times of the ionospheric precursors scale with the earthquake magnitude, confirming the validity of the Rikitake law for ionospheric signals, previously valid for ground precursors. We also find that the anomaly duration seems to depend on the magnitude of the impending earthquake. Finally, we propose a simple scheme of potential earthquake forecast on the base of the previously mentioned characteristics.</p>

Experimental evidence of the correlation between possible precursors of earthquakes in near-surface quasistatic electric fields and in the ionosphere

2010 ◽  
Vol 50 (7) ◽  
pp. 920-926 ◽  
Author(s):  
L. P. Korsunova ◽  
Yu. M. Mikhailov ◽  
V. V. Khegai ◽  
L. N. Leshchenko ◽  
S. E. Smirnov ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Electric Fields ◽  
Near Surface ◽  
Precursors Of Earthquakes

scholarly journals Short-term electromagnetic precursors of earthquakes

2019 ◽  
Vol 10 (3) ◽  
pp. 731-740
Author(s):  
B. V. Dovbnya ◽  
A. Yu. Pashinin ◽  
R. A. Rakhmatulin
Keyword(s):  
Short Term ◽  
Precursors Of Earthquakes ◽  
Electromagnetic Precursors

scholarly journals Variations of ionospheric and geomagnetic field parameters during the June 18, 2013 Bachat earthquake

2021 ◽  
Vol 7 (1) ◽  
pp. 98-105
Author(s):  
Anastasiya Belinskaya ◽  
Aleksandr Kovalev ◽  
Nikolay Semakov ◽  
Sofiya Belinskaya
Keyword(s):  
Magnetic Moment ◽  
Sharp Increase ◽  
Critical Frequency ◽  
Sharp Decrease ◽  
Night Time ◽  
The Third ◽  
Subsequent Period ◽  
Time Region ◽  
Magnetic Constant ◽  
Precursors Of Earthquakes

The paper presents the results of a study of variations in ionospheric parameters and local magnetic constant before, during, and after the Вachat earthquake, which occurred on June 18, 2013 at 23:02 UT (June 19, 2013 at 06:02 LT) with a magnitude 5.3–5.6 and epicenter coordinates 54.29° N, 86.17° E. We have used data from IPGG SB RAS and TSU ionospheric stations and INTERMAGNET geomagnetic observatories. We have established that in the period preceding the earthquake there was a rather sharp increase in the magnetic moment, and in the subsequent period there was an equally sharp decrease in the magnetic moment. It is noted that the analysis of the daily average values of the local magnetic constant is the most promising for searching for geomagnetic precursors of earthquakes. We have found a low strong sporadic layer Es for two days before the event, the like of which was not observed for 15 days before and 15 days after the event. In addition, on the days preceding the shock, the background values of the F2-layer critical frequency were larger by more than 20 % at the local pre-event hours. On the second day after the earthquake, there appeared a night-time region of low values (about 14 %), which persisted until the morning of the third day.

scholarly journals Variations of ionospheric and geomagnetic field parameters during the June 18, 2013 Bachat earthquake

2021 ◽  
Vol 7 (1) ◽  
pp. 78-84
Author(s):  
Anastasiya Belinskaya ◽  
Aleksandr Kovalev ◽  
Nikolay Semakov ◽  
Sofiya Belinskaya
Keyword(s):  
Magnetic Moment ◽  
Sharp Increase ◽  
Critical Frequency ◽  
Sharp Decrease ◽  
Night Time ◽  
The Third ◽  
Subsequent Period ◽  
Time Region ◽  
Magnetic Constant ◽  
Precursors Of Earthquakes

The paper presents the results of a study of variations in ionospheric parameters and local magnetic constant before, during, and after the Vachat earthquake, which occurred on June 18, 2013 at 23:02 UT (June 19, 2013 at 06:02 LT) with a magnitude 5.3–5.6 and epicenter coordinates 54.29 ° N, 86.17 ° E. We have used data from IPGG SB RAS and TSU ionospheric stations and INTERMAGNET geomagnetic observatories. We have established that in the period preceding the earthquake there was a rather sharp increase in the magnetic moment, and in the subsequent period there was an equally sharp decrease in the magnetic moment. It is noted that the analysis of the daily average values ​​of the local magnetic constant is the most promising for searching for geomagnetic precursors of earthquakes. We have found a low strong sporadic layer Es for two days before the event, the like of which was not observed for 15 days before and 15 days after the event. In addition, on the days preceding the shock, the background values ​​of the F2-layer critical frequency were larger by more than 20% at the local pre-event hours. On the second day after the earthquake, there appeared a night-time region of low values ​​(about 14%), which persisted until the morning of the third day.

scholarly journals PHASE REARRANGEMENT IN LOCAL BALANCED HYDROGEOCHEMICAL SYSTEMS AS A OF FLUID EARTHQUAKE PRECURSORS MECHANISM OCCURRENCE

2019 ◽  
Vol 16 (33) ◽  
pp. 248-258
Author(s):  
A. U. ABDULLAEV
Keyword(s):  
Earthquake Prediction ◽  
Structural Relaxation ◽  
Earthquake Precursors ◽  
Strong Earthquakes ◽  
Major Earthquake ◽  
Time Period ◽  
Internal Phase ◽  
The World ◽  
Precursors Of Earthquakes ◽  
Hydrogeochemical System

Scientists all over the world are making tremendous efforts to solve the problem of earthquake prediction. Dozens of different phenomena and signs that could serve as precursors of earthquakes are found. But these effects were very unstable and had a mosaic character in the propagation of development and time. They appeared not always and not before every major earthquake. There are many cases where earthquakes occurred without the manifestation of any precursors. Such non-stationary phenomena do not allow formulating adequate strong earthquakes preparing models and their methods of predicting. Among well-studied and encouraging earthquake precursors, hydrogeodynamic and hydrogeochemical anomalies are considered to be the most promising, which has a sufficiently substantiated scientific background. In this class of precursors, the mechanism of their formation during the preparation of earthquakes remains debatable. There are several problems due to abnormal concentration sources and their transport during a little time period in the observation points. In the proposed work, it is proved that the main mechanism of the occurrence of exotic transient fluid anomalies is the interphase rearrangement in the local balanced hydrogeochemical system as a reaction to strong earthquakes factors preparing influence. The internal phase reorganization in the hydrogeochemical system is realized through structural relaxation as a result of the occurrence of rapid physicochemical reactions exchange.

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