## Everyday Monitoring

## Geomagnetic quakes as Earthquake Precursor

Every day Sofia (one component) and Skopje, Kiev (vector variometer mode) geomagnetic and earthquake monitoring.
The analysis of Kiev data for estimation of geomagnetic quake (the value of Sig jump) need more statistic.
Explanation for the next Sofia, Skopje, Kiev, Lvov,Pag and Dusheti, Georgia (DSH_Ge) grafics: The earthquake precursor
(geomagnetic quake) is SigD 10% jump. The approximate time window for incoming event is
defined from the next Earth Tide extrem (Dennis Milbert source ccde). In minimum the
time period is approximately ±1 day and in maximum ±2 days.

EQ data from:http://wwwneic.cr.usgs.gov/neis/bulletin/

Reliability time control from:http://www.emsc-csem.org/

SChtM>2e4, Mag>3, Distance<800 km. The index of SChtM is the time difference between local Tide extremum and occred Eq time.
The index of Magnitude is the distance in hundred km between Gm device and eq's epicenter.

p.s.Nov 09, 2011 In our (me and Lazo Pekevski) visit in Georgia in the framework of EU FP7 IRSES 2011 Project "Complex research of earthquake'e forecasting possibilities,seismicity and Climate chang correlations"

http://theo.inrne.bas.bg/~mavrodi/BlackSeaHazNet_html

the Dusheti, Georgia flux gate magnetometer data were included in our every day monitoring.

p.s.Aug 01, 2013 In our (me and Lazo Pekevski) visit in Grocka, Serbia in July in collaboration with Milena Cukavac and Dr. Spomenko Mihailovich
the Grocka flux gate magnetometer data were included in our every day monitoring.

Last visit

*Blog Counters*

December 21, 2014

Important note: Please see the explanations for the developing the "Geomagnetic approach" in the time of EU IRSES BlackSeaHazNet (2011-2014) project:
**
BlackSeaHazNet Scientific Report - EU FP7 IRSES project 2011-2014**

Last udate:

08 Apr 2008 SofiaBg

06 Jan 2014 Skopje Skopje, Macedonia

20 Jul 2017 Kiev Kiev, Ukraine

06 Jan 2014 Lvov Lvov, Ukraine

03 Apr 2018 Pag Panagurichte, Bg

21 Sep 2012 DSHGe Dusheti, Georgia

03 Apr 2018 GckSrb Grocka, Belgrade, Serbia

03 Apr 2018 SuaRo Surlari, Romania

06 Feb 2014 LAquila LAquila, Italy

21 Mar 2015 ArmeniaGeomagnetic Stepanavan, Armenia

06 Feb 2014 ArmeniaBoreHole Noemberyan borehole, Armenia

24 Aug 2017 KAK Kakioka, Japan

**Real time EMSC-CSEM reliability test,**

## Explanation

It is useful to stress that the author’s interests to the earthquake’s prediction problem arise as a result of complex research of the
Black Sea ecosystem about 15 years ago (Mavrodiev, 1998). During the time of gathering the historical data for the ecosystem was observed,
that the Crime earthquake in 1928 occurred, as an evidence for electromagnetic and earthquake correlations. Such hypothesis has been proposed
by the academician Popov in the early 20- 30-ties of the last century (private communication).

According the INTERMAGNET requirements for measuring the geomagnetic field (see Fig.1) on Earth surface (http://www.intermagnet.org),
the accuracy is ±10 nT for 95% of reported data and ±5 nT for definitive data, with one sample per 5 seconds, in the case of Vector magnetometer
(F(XYZ) or F(HDZ)) and 1 nT, with 3 samples per second, for Scalar Magnetometer (F).

The geomagnetic vector projection H is measured with relative accuracy less or equal to1 nT by a fluxgate, feedback based device of rather
original and simple, but powerful construction. (know- how of JINR, Dubna, Boris Vasiliev, 1998, private communication). It is used with 2.4
samples per second. Due to technical reasons the sensor was oriented under the Horizon in a manner that the measured value of H is around 20000
nT (Figures 1 and 2).

The minute averaged value and it’s error are
and ,

where ,
are the measured Nm=144 times per values of the field and their experimental error. The standard deviation
and it’s error for every minute are:

Analyzing the correlations between the behavior of the geomagnetic field, Earth tidal gravitational potential and the occurred earthquakes
(1999 to 2001) it turns out that the daily averaged value of ( and ),
which we denote by Sig (dSig), is playing the role of earthquake precursor.

Figure 3 illustrates the behavior of geomagnetic field component and its variation for a period without earthquakes precursor in the region. Figures 4 and 5 illustrate the behavior of geomagnetic field and its variation, which is unusual. Is this case there is a geomagnetic quake, which is precursor for incoming event (earthquake or earthquakes). One has to be sure that there are not a cosmos or Sun wind reasons for the geomagnetic quake ( see the site:http://www.sec.noaa.gov/rt_plots/satenv.html )

For example. in Figure 4 the predicted time was 3 +/- 1 June, 2002 and the prediction was confirmed with earthquake, occurred at 03/06/2002 02:04, Lat41.95N,
Lon23.10E, Dep8, Mag2.6, Ml, 50 km from Sofia, SChtM = 598 [Mag/r2].

The preliminary Fourier analysis of data gives the fact that the bigger geomagnetic variations are cased from the arriving for hours time
period new frequencies with periods from 10-th of seconds till 10-th of minutes and with very specific amplitude behavior. Such spectrum,
which arrives for hour period of time, is invisible for minute samples measuring.

The probability time window of the incoming event (or events) is defined by the next date of the Earth tidal potential extremum with tolerance
approximately for the tidal minimum +/-1 day and for the maximum +/-2 days- Figure 6.

The uncertainty problem of distinguishing the predicted event (or group of events – aftershocks) from the events which occurred in the region in the
predicted time window is solved with new earthquake function S_{ChtM}:

The sense of function S_{ChtM} is a density distribution of earthquake's Magnitude. In the point of measurement S_{ChtM} is logarithmically proportional
to the energy influence of the earthquakes. It is important to stress out that the first consideration of the Magnitude and distance dependences was obtained on the basis
of nonlinear inverse problem methods. Obviously, the nearer and biggest earthquake (relatively biggest value of S_{ChtM}) will bear more electropotential variations, which will generate more
power geomagnetic quake. At this stage of the researching the measure of daily geomagnetic state can serve the averaged for 24 hours (1440 minutes) values of standard deviations:

The simple and usually working criterion for evidence of geomagnetic quake is when Sig increases for two consecutive days i, i+1 and the differences between the values
of Sig are bigger than the mean arithmetic sum of their errors dSig:

(2) Abs(Sig _{i+1} - Sig _{i}) > (Dsig _{i}+ DSig _{i+1})/2.

If criteria (2) are fulfilled and there are not a Cosmos and Sun generated variations of geomagnetic field, it could be concluded that
the geomagnetic quake has happened. Such quake is unique precursor for incoming earthquake and in the next minimum or maximum of the
local Tidal gravitational potential somewhere in the region this predicted earthquake will occur. For some of the cases, the criteria
(2) have to be calculated for decades of hours or ten’s of minutes. The signal for earthquakes with different epicenters we observe in
the case when the specific behavior of field and its standard deviation occurs more than ones per day at different hours.

The analysis of the precursor function Sig on the basis of special digital 5 points derivatives can serve in the future for creating
the algorithm for automated alert system.It is obvious that the more detailed time window can be achieved by analyzing the daily variations
of tidal potential, calculated every hour.

As an example, the parameters of predicted events (Figure 5) are presented in Table 1.

## Table 1

DMYhm | Latitude Longitude | Dept [km] | Magnitude | Distance [hundred km] | ChtM |
---|---|---|---|---|---|

03/07/2003 15:49 | 42.96 25.29 | 10 | 2.6 | 1.10 | 219 |

03/07/2003 20:51 | 41.96 23.28 | 12 | 2.9 | 0.48 | 684 |

05/07/2003 21:58 | 40.35 26.14 | 2 | 4.0 | 2.97 | 70 |

06/07/2003 19:10 | 40.46 26.01 | 10 | 5.7 | 3.16 | 89 |

06/07/2003 19:39 | 40.62 25.25 | 2 | 4.2 | 2.35 | 111 |

06/07/2003 20:02 | 40.72 25.98 | 20 | 3.2 | 2.54 | 71 |

06/07/2003 20:10 | 40.46 26.08 | 10 | 5.0 | 3.20 | 76 |

06/07/2003 20:48 | 40.28 26.08 | 2 | 4.1 | 3.01 | 70 |

06/07/2003 21:58 | 40.38 26.10 | 10 | 3.9 | 2.92 | 70 |

06/07/2003 22:05 | 40.34 26.00 | 2 | 3.9 | 2.92 | 71 |

06/07/2003 22:42 | 40.95 26.00 | 10 | 4.6 | 2.80 | 89 |

07/07/2003 00:24 | 40.25 25.98 | 2 | 3.7 | 3.00 | 64 |

07/07/2003 00:48 | 40.44 25.87 | 18 | 3.4 | 2.77 | 66 |

07/07/2003 07:15 | 41.67 24.88 | 10 | 3.1 | 1.21 | 230 |

07/07/2003 16:17 | 40.37 25.91 | 10 | 3.3 | 2.85 | 61 |

08/07/2003 02:48 | 41.82 22.93 | 12 | 2.8 | 0.65 | 465 |

08/07/2003 12:00 | 42.84 23.32 | 10 | 2.5 | 0.50 | 565 |

At this stage of the study all earthquakes have the same S_{ChtM} for different definitions of the magnitude.
After the developing of mathematical models of empirical and theoretical dependences between incoming earthquake processes,
magnetic quake and parameters of earthquake on the basis of inverse nonlinear problem we will obtain a set of S_{ChtM}
functions in correspondence with the different definition of magnitude. The volumes, its depth, chemical and geological structures
of the region have to be included in the
dependences as well.

From January 1, 2004 is using function S_{ChtM}, which is the density of earthquake energy in the measurement point:

S_{ChtM}=exp( Magnitude ) / (R_{eq}+Distance)^{2}, R_{eq} = 0.40+Dept [hundred km]

The other variables are the same.

In the vernal and autumnal equinox the approach (2) needs more statistics on the bases of geomagnetic data from at least 3 monitoring
points for discovering the more hidden dependences between geomagnetic quakes, more flatter tidal variations and incoming event or events.

SChtM/June 2004, Sofia