Correlations between Earthquake Properties and Characteristics of Possible ULF Geomagnetic Precursor over Multiple Earthquakes

In this study, we improved and adapted existing signal processing methods on vast geomagnetic field data to investigate the correlations between various earthquake properties and characteristics of possible geomagnetic precursors. The data from 10 magnetometer stations were utilized to detect precursory ultra-low frequency emission and estimate the source direction for 34 earthquakes occurring between the year 2007–2016 in Southeast Asia, East Asia, and South America regions. As a result, possible precursors of 20 earthquakes were identified (58.82% detection rate). Weak correlations were obtained when all precursors were considered. However, statistically significant and strong linear correlations (r ≥ 0.60, p < 0.05) were found when the precursors from two closely located stations in Japan (Onagawa (ONW) and Tohno (TNO)) were exclusively investigated. For these stations, it was found that the lead time of the precursor is strongly (or very strongly) correlated with the earthquake magnitude, the local seismicity index, and the hypocentral depth. In addition, the error percentage of the estimated direction showed a strong correlation with the hypocentral depth. It is concluded that, when the study area is restricted to a specific location, the earthquake properties are more likely to have correlations with several characteristics of the possible precursors.

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Geomagnetic anomaly associated with Fukushima earthquake on February 13th, 2021

E3S Web of Conferences ◽

10.1051/e3sconf/202133107012 ◽

2021 ◽

Vol 331 ◽

pp. 07012

Author(s):

Cipta Ramadhani ◽

Bulkis Kanata ◽

Abdullah Zainuddin ◽

Rosmaliati ◽

Teti Zubaidah

Keyword(s):

Data Processing ◽

Geomagnetic Field ◽

Field Data ◽

Low Frequency ◽

Earthquake Precursors ◽

Polarization Ratio ◽

Magnetic Polarization ◽

Central Frequency ◽

Electromagnetic Data ◽

Geomagnetic Anomaly

In this study, we performed research on electromagnetic anomalies related to earthquakes as early signs (precursors) that occurred in Fukushima, Japan on February 13th, 2021. The research focused on the utilization of geomagnetic field data which was derived from the Kakioka (KAK), Kanoya (KNY), and Memambetsu (MMB) observatories, particularly in the ultra-low frequency (ULF) to detect earthquake precursors. The method of electromagnetic data processing was conducted by applying a polarization ratio. In addition, we improved the methodology by splitting the ULF data (which ranged from 0.01-0.1 Hz) into 9 central frequencies and picking up the highest value from each central frequency to get the polarization ratio. The anomaly of magnetic polarization was identified 2-3 weeks before the mainshock in a narrowband frequency in the range of 0.04-0.05 Hz.

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Review Article: On the relation between the seismic activity and the Hurst exponent of the geomagnetic field at the time of the 2000 Izu swarm

Natural Hazards and Earth System Science ◽

10.5194/nhess-13-2189-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 2189-2194 ◽

Cited By ~ 5

Author(s):

F. Masci ◽

J. N. Thomas

Keyword(s):

Geomagnetic Activity ◽

Geomagnetic Field ◽

Seismic Activity ◽

Hurst Exponent ◽

Field Data ◽

Low Frequency ◽

Review Article ◽

Magnetic Disturbances

Abstract. Many papers document the observation of earthquake-related precursory signatures in geomagnetic field data. However, the significance of these findings is ambiguous because the authors did not adequately take into account that these signals could have been generated by other sources, and the seismogenic origin of these signals have not been validated by comparison with independent datasets. Thus, they are not reliable examples of magnetic disturbances induced by the seismic activity. Hayakawa et al. (2004) claim that at the time of the 2000 Izu swarm the Hurst exponent of the Ultra-Low-Frequency (ULF: 0.001–10 Hz) band of the geomagnetic field varied in accord with the energy released by the seismicity. The present paper demonstrates that the behaviour of the Hurst exponent was insufficiently investigated and also misinterpreted by the authors. We clearly show that during the Izu swarm the changes of the Hurst exponent were strongly related to the level of global geomagnetic activity and not to the increase of the local seismic activity.

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Review "On the relation between the seismic activity and the Hurst exponent of the geomagnetic field at the time of the 2000 Izu swarm"

Natural Hazards and Earth System Sciences Discussions ◽

10.5194/nhessd-1-681-2013 ◽

2013 ◽

Vol 1 (2) ◽

pp. 681-691 ◽

Cited By ~ 1

Author(s):

F. Masci ◽

J. N. Thomas

Keyword(s):

Geomagnetic Activity ◽

Geomagnetic Field ◽

Seismic Activity ◽

Hurst Exponent ◽

Field Data ◽

Low Frequency ◽

Magnetic Disturbances

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USING FIELD DATA FOR THE EVALUATION OF THE IMPACT OF ULTRA-LOW FREQUENCY MOTIONS ON THE FATIGUE OF MOORING LINES

10.26678/abcm.cobem2019.cob2019-0608 ◽

2019 ◽

Author(s):

Guilherme Borzacchiello ◽

Carl Albrecht ◽

Fabricio N Correa ◽

Breno Jacob ◽

Guilherme da Silva Leal

Keyword(s):

Field Data ◽

Low Frequency ◽

Mooring Lines ◽

The Impact

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Polarization pattern of low-frequency geomagnetic field fluctuations (0.8-3.6 mHz) at high and low latitude

Journal of Geophysical Research Atmospheres ◽

10.1029/1998ja900002 ◽

1999 ◽

Vol 104 (A1) ◽

pp. 305-310 ◽

Cited By ~ 9

Author(s):

S. Lepidi ◽

P. Francia ◽

U. Villante ◽

L. J. Lanzerotti ◽

A. Meloni

Keyword(s):

Geomagnetic Field ◽

Low Frequency ◽

Polarization Pattern ◽

Low Latitude ◽

Field Fluctuations

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Design of PLC Integrated Process Simulation Software for Steam Generator Using Matlab Simulink

E3S Web of Conferences ◽

10.1051/e3sconf/20184301012 ◽

2018 ◽

Vol 43 ◽

pp. 01012

Author(s):

Ikhtiander ◽

Soekirno Santoso

Keyword(s):

Steam Generator ◽

Flow Rate ◽

Field Data ◽

Volume Flow ◽

Differential Pressure ◽

Steam Quality ◽

Fuel Gas ◽

Matlab Simulink ◽

Simulator Program ◽

Error Percentage

This paper describes the work done in order to make Matlab Simulink based steam generator simulator in the simulation of a steam generator. The steam generator under this research is operated with the steam quality of 72%, O2 content is 1.2%, designed steam volume flow is 3600 barrel per day at a maximum and designed fuel gas volume flow is 1300 Thousand Standard Cubic Feet (MSCF) per day at a maximum. The simulator program of the steam generator is separated into individual components consisting of Burner, Radiant, Convection, Exhaust Stack, Feedwater Pump Discharge and Steam Discharge. Within the components, thermodynamics and heat transfer principles such as conduction, convection, radiation and also conservation of mass, momentum, and energy were applied to compute the pressure values, temperature values, and flow rate values of simulated field device based on the command and setpoint from PLC. The validation process has been done with the steam generator is operating in a steady state to the 10 important process parameters of the steam generator. The error percentage calculated from a difference between the simulation result value and the actual value from field data reference divide by actual value from field data reference. The error percentage results are as following : Fuel Gas Orifice Differential Pressure : 2.39%, Fuel Gas Pressure : 1.37%, Fuel Gas Temperature : 5.95%, Fuel Gas Flow Rate : 1.25%, Feedwater Orifice Differential Pressure : 1.94%, Feedwater Pressure : 1.54%, Feedwater Flow Rate : 0.92%, Steam Orifice Differential Pressure 3.26%, Steam Discharge Pressure 1.93% and Steam Quality : 0.05%.

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Influence of high-latitude geomagnetic pulsations on recordings of broadband force-balanced seismic sensors

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-1-85-2012 ◽

2012 ◽

Vol 1 (2) ◽

pp. 85-101 ◽

Cited By ~ 2

Author(s):

E. Kozlovskaya ◽

A. Kozlovsky

Keyword(s):

Magnetic Field ◽

Geomagnetic Field ◽

Geomagnetic Latitude ◽

Low Frequency ◽

Auroral Oval ◽

Polar Regions ◽

Geomagnetic Pulsations ◽

Seismic Sensors ◽

Magnetic Poles ◽

Magnetic Disturbances

Abstract. Seismic broadband sensors with electromagnetic feedback are sensitive to variations of surrounding magnetic field, including variations of geomagnetic field. Usually, the influence of the geomagnetic field on recordings of such seismometers is ignored. It might be justified for seismic observations at middle and low latitudes. The problem is of high importance, however, for observations in Polar Regions (above 60° geomagnetic latitude), where magnitudes of natural magnetic disturbances may be two or even three orders larger. In our study we investigate the effect of ultra-low frequency (ULF) magnetic disturbances, known as geomagnetic pulsations, on the STS-2 seismic broadband sensors. The pulsations have their sources and, respectively, maximal amplitudes in the region of the auroral ovals, which surround the magnetic poles in both hemispheres at geomagnetic latitude (GMLAT) between 60° and 80°. To investigate sensitivity of the STS-2 seismometer to geomagnetic pulsations, we compared the recordings of permanent seismic stations in northern Finland to the data of the magnetometers of the IMAGE network located in the same area. Our results show that temporary variations of magnetic field with periods of 40–150 s corresponding to regular Pc4 and irregular Pi2 pulsations are seen very well in recordings of the STS-2 seismometers. Therefore, these pulsations may create a serious problem for interpretation of seismic observations in the vicinity of the auroral oval. Moreover, the shape of Pi2 magnetic disturbances and their periods resemble the waveforms of glacial seismic events reported originally by Ekström (2003). The problem may be treated, however, if combined analysis of recordings of co-located seismic and magnetic instruments is used.

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The geomagnetic field at 1982 from DE-2 and other magnetic field data.

Journal of geomagnetism and geoelectricity ◽

10.5636/jgg.40.1103 ◽

1988 ◽

Vol 40 (9) ◽

pp. 1103-1127 ◽

Cited By ~ 10

Author(s):

R. A. LANGEL ◽

J. R. RIDGWAY ◽

M. SUGIURA ◽

K. MAEZAWA

Keyword(s):

Magnetic Field ◽

Geomagnetic Field ◽

Field Data ◽

Magnetic Field Data

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Laplace-domain full-waveform inversion of seismic data lacking low-frequency information

Geophysics ◽

10.1190/geo2011-0411.1 ◽

2012 ◽

Vol 77 (5) ◽

pp. R199-R206 ◽

Cited By ~ 31

Author(s):

Wansoo Ha ◽

Changsoo Shin

Keyword(s):

Seismic Data ◽

Field Data ◽

Waveform Inversion ◽

Low Frequency ◽

Single Frequency ◽

Frequency Content ◽

Laplace Domain ◽

Frequency Information ◽

Velocity Models ◽

Gaussian Source

The lack of the low-frequency information in field data prohibits the time- or frequency-domain waveform inversions from recovering large-scale background velocity models. On the other hand, Laplace-domain waveform inversion is less sensitive to the lack of the low frequencies than conventional inversions. In theory, frequency filtering of the seismic signal in the time domain is equivalent to a constant multiplication of the wavefield in the Laplace domain. Because the constant can be retrieved using the source estimation process, the frequency content of the seismic data does not affect the gradient direction of the Laplace-domain waveform inversion. We obtained inversion results of the frequency-filtered field data acquired in the Gulf of Mexico and two synthetic data sets obtained using a first-derivative Gaussian source wavelet and a single-frequency causal sine function. They demonstrated that Laplace-domain inversion yielded consistent results regardless of the frequency content within the seismic data.

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Extremely low-frequency pulses of faint magnetic field, weaker than the geomagnetic field, induce mitophagy to rejuvenate mitochondria

10.21203/rs.3.rs-528037/v1 ◽

2021 ◽

Author(s):

Takuro Toda ◽

Mikako Ito ◽

Jun-ichi Takeda ◽

Alkio Masuda ◽

Nobutaka Hattori ◽

...

Keyword(s):

Magnetic Fields ◽

Geomagnetic Field ◽

Low Frequency ◽

Mitochondrial Mass ◽

Complex Ii ◽

Extremely Low Frequency ◽

Mitochondrial Homeostasis ◽

Weak Magnetic Fields ◽

Transport Chain ◽

Chemical Inhibition

Abstract Humans are frequently exposed to time-varying and static weak magnetic fields (WMF). However, the effects of faint magnetic fields, weaker than the geomagnetic field, have not been reported. We found that extremely low-frequency (ELF)-WMF, comprised of serial pulses of 10 µT intensity at 1–8 Hz, which was three or more times weaker than the geomagnetic field, reduced mitochondrial mass to 70% and the mitochondrial electron transport chain (ETC) complex II activity to 88%. Chemical inhibition of electron flux through the mitochondrial ETC complex II nullified the effect of ELF-WMF. Suppression of ETC complex II subsequently induced mitophagy by translocating parkin and PINK1 to the mitochondria and by recruiting LC3-II. Thereafter, mitophagy induced PGC-1α-mediated mitochondrial biogenesis to rejuvenate mitochondria. The lack of PINK1 negated the effect of ELF-WMF. Thus, ELF-WMF may be applicable for the treatment of human diseases that exhibit compromised mitochondrial homeostasis, such as Parkinson’s disease.

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