Strong earthquake activity influenced by solar flare intensity

2021 ◽  
Author(s):  
Gerald Duma
Keyword(s):  
Solar Flares ◽  
Strong Earthquake ◽  
Temporal Variations ◽  
Seasonal Effect ◽  
Earthquake Activity ◽  
Strong Earthquakes ◽  
International Service ◽  
Earthquake Frequency ◽  
Magnetic Index ◽  
Magnetic Disturbances

<p>Based on the comprehensive earthquake catalogue USGS ( HYPERLINK<span>  </span>https://earthquake.usgs.gov) the paper demonstrates that strong earthquake activity, seismic events with M≥6, exhibits a seasonal trend. This feature is the result of<span>  </span>analyses of earthquake data for the N- and S- Earth Hemisphere in period 2010-2019. It can be shown also for single earthquake prone regions as well, like Japan, Eurasia, S-America.</p><p>Any seasonal effect suggests an external influence. In that regard, one can think also of a solar-terrestrial effect, that is suggested already in several studies (e.g<span>  </span>M.Tavares, A.Azevedo, 2011; D.A.E. Vares, M.A.Persinger,2014; G.Duma, 2019). This assumption leads to the question: Which dynamic process can cause a trigger effect for strong earthquakes in the Earth's lithosphere.</p><p>In this study the intensity of solar flares and the resulting radiation, the solar wind, towards the Earth was taken into account. An appropriate parameter which has been regularity measured and reported for many decades and which reflects the intensity of solar radiation is the magnetic index Kp. It is measured at numerous geomagnetic observatories and describes the magnetic disturbances in nT within 3 hour intervals, respectively. Averages of all the measured 3-hour values are then published as Kp, therefore considered a planetary parameter (International Service of Geomagnetic Indices ISGI,France).</p><p>The temporal variations of strong earthquake activity over 10 years and their energy release was compared with the above mentioned index Kp. Actually, a distinct correlation between the two quantities, Kp and earthquake frequency, resulted in cases of different regions as well as globally. Another essential result of the study is that maxima of Kp preceed those of earthquake activity by about 60 to 80 days in most cases. The mechanism has not yet been modeled satisfactorily.</p>

scholarly journals Strong earthquakes can be predicted: a multidisciplinary method for strong earthquake prediction

2003 ◽  
Vol 3 (6) ◽  
pp. 703-712 ◽  
Author(s):  
J. Z. Li ◽  
Z. Q. Bai ◽  
W. S. Chen ◽  
Y. Q. Xia ◽  
Y. R. Liu ◽  
...  
Keyword(s):  
Earthquake Prediction ◽  
Strong Earthquake ◽  
Low Frequency ◽  
Abnormal Behavior ◽  
Frequency Range ◽  
Strong Earthquakes ◽  
Physical Mechanisms ◽  
Innovative Methods ◽  
The World ◽  
Infrasonic Wave

Abstract. The imminent prediction on a group of strong earthquakes that occurred in Xinjiang, China in April 1997 is introduced in detail. The prediction was made on the basis of comprehensive analyses on the results obtained by multiple innovative methods including measurements of crustal stress, observation of infrasonic wave in an ultra low frequency range, and recording of abnormal behavior of certain animals. Other successful examples of prediction are also enumerated. The statistics shows that above 40% of 20 total predictions jointly presented by J. Z. Li, Z. Q. Ren and others since 1995 can be regarded as effective. With the above methods, precursors of almost every strong earthquake around the world that occurred in recent years were recorded in our laboratory. However, the physical mechanisms of the observed precursors are yet impossible to explain at this stage.

scholarly journals Identification of Precursory Anomalies before Moderate-strong Earthquakes in Junction of Shanxi-Hebei-Inner Mongolia Area

2020 ◽  
Vol 206 ◽  
pp. 01011
Author(s):  
Li Hong
Keyword(s):  
Standard Deviation ◽  
Inner Mongolia ◽  
Strong Earthquake ◽  
Earthquake Magnitude ◽  
Parameter Analysis ◽  
Time Interval ◽  
Study Region ◽  
Strong Earthquakes ◽  
Spectrum Method ◽  
Prediction Efficiency

In this paper, we take the Junction of Shanxi-Hebei-Inner Mongolia area as study region using earthquake corresponding relevancy spectrum method (ECRS method) to identify comprehensive precursory anomalies before moderate-strong earthquake. On base of single-parameter relevancy spectrum database with target earthquake magnitude as Ms4.7 and initial earthquake magnitude as Ms1, we carry on multi-parameter analysis and find that result with time interval of 9 months and anomaly threshold with 0.40 times standard deviation has better prediction efficiency. Its anomaly corresponding rate and earthquake corresponding rate are 6/10 and 9/9 respectively.

scholarly journals Comparison of simultaneous variations of the ionospheric total electron content and geomagnetic field associated with strong earthquakes

2001 ◽  
Vol 1 (1/2) ◽  
pp. 53-59 ◽  
Author(s):  
Sh. Naaman ◽  
L. S. Alperovich ◽  
Sh. Wdowinski ◽  
M. Hayakawa ◽  
E. Calais
Keyword(s):  
Total Electron Content ◽  
Vertical Displacement ◽  
Temporal Variations ◽  
Electron Content ◽  
Geomagnetic Disturbances ◽  
Total Electron ◽  
Strong Earthquakes ◽  
Ionospheric Total Electron Content ◽  
Geomagnetic Observations ◽  
Gps Observations

Abstract. In this paper, perturbations of the ionospheric Total Electron Content (TEC) are compared with geomagnetic oscillations. Comparison is made for a few selected periods, some during earthquakes in California and Japan and others at quiet periods in Israel and California. Anomalies in TEC were extracted using Global Positioning System (GPS) observations collected by GIL (GPS in Israel) and the California permanent GPS networks. Geomagnetic data were collected in some regions where geomagnetic observatories and the GPS network overlaps. Sensitivity of the GPS method and basic wave characteristics of the ionospheric TEC perturbations are discussed. We study temporal variations of ionospheric TEC structures with highest reasonable spatial resolution around 50 km. Our results show no detectable TEC disturbances caused by right-lateral strike-slip earthquakes with minor vertical displacement. However, geomagnetic observations obtained at two observatories located in the epicenter zone of a strong dip-slip earthquake (Kyuchu, M = 6.2, 26 March 1997) revealed geomagnetic disturbances occurred 6–7 h before the earthquake.

scholarly journals The 2018 Geothermal Reservoir Stimulation in Espoo/Helsinki, Southern Finland: Seismic Network Anatomy and Data Features

2020 ◽  
Vol 91 (2A) ◽  
pp. 770-786
Author(s):  
Gregor Hillers ◽  
Tommi A. T. Vuorinen ◽  
Marja R. Uski ◽  
Jari T. Kortström ◽  
Päivi B. Mäntyniemi ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Signal To Noise Ratio ◽  
Body Wave ◽  
Temporal Variations ◽  
Seismic Network ◽  
Anthropogenic Activity ◽  
Earthquake Activity ◽  
Velocity Change ◽  
Fault Plane Solutions ◽  
Induced Earthquake

Abstract A seismic network was installed in Helsinki, Finland to monitor the response to an ∼6-kilometer-deep geothermal stimulation experiment in 2018. We present initial results of multiple induced earthquake seismogram and ambient wavefield analyses. The used data are from parts of the borehole network deployed by the operating St1 Deep Heat Company, from surface broadband sensors and 100 geophones installed by the Institute of Seismology, University of Helsinki, and from Finnish National Seismic Network stations. Records collected in the urban environment contain many signals associated with anthropogenic activity. This results in time- and frequency-dependent variations of the signal-to-noise ratio of earthquake records from a 260-meter-deep borehole sensor compared to the combined signals of 24 collocated surface array sensors. Manual relocations of ∼500 events indicate three distinct zones of induced earthquake activity that are consistent with the three clusters of seismicity identified by the company. The fault-plane solutions of 14 selected ML 0.6–1.8 events indicate a dominant reverse-faulting style, and the associated SH radiation patterns appear to control the first-order features of the macroseismic report distribution. Beamforming of earthquake data from six arrays suggests heterogeneous medium properties, in particular between the injection site and two arrays to the west and southwest. Ambient-noise cross-correlation functions reconstruct regional surface-wave propagation and path-dependent body-wave propagation. A 1D inversion of the weakly dispersive surface waves reveals average shear-wave velocities around 3.3  km/s below 20 m depth. Consistent features observed in relative velocity change time series and in temporal variations of a proxy for wavefield partitioning likely reflect the medium response to the stimulation. The resolution properties of the obtained data can inform future monitoring strategies and network designs around natural laboratories.

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