EGU2020-13795
https://doi.org/10.5194/egusphere-egu2020-13795
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Possible correlation beteen the pre-seismic geomagnetic signal and the M6.4 earthquake generated in the coastal zone of Albania, on November 26, 2019

Dumitru Stanica and Dragos Armand Stanica
Dumitru Stanica and Dragos Armand Stanica
  • Institute of Geodynamics, Electromagnetism and Lithosphere Dynamics, Bucharest, Romania (armand@geodin.ro)

A catastrophic earthquake of magnitude Mw6.4 generated at 10km depth hit coastal zone of Albania on November 26-th 2019, at 2h54min UTC. The earthquake was intensively felt at about 34km far, in Tirana City, where a lot of damages have occurred. Consequently, in order to identify the anomalous geomagnetic signature before the onset of this earthquake, we retrospectively analyzed the data collected on the interval October 15–November 30, 2019 at the two geomagnetic observatories: Panagjurishte (PAG)-Bulgaria and Surlari (SUA)-Romania, the last one taken as reference. The pre-seismic geomagnetic anomalous signal is postulated to be due to the electrical conductivity changes, most probably associated with the earthquake-induced tectonic stress, followed by rupture and electrochemical processes deployed along the Adria plate subduction zone. To identify a pre-seismic geomagnetic signal related to this earthquake we used: (i) polarization parameter BPOL which should be time invariant in non-seismic condition and it becomes unstable before the onset a seismic event; (ii) Strain effect-related to the anomalous geomagnetic signals identification. Thus, the daily mean distributions of the BPOL and its standard deviations (SD) are performed for the both observation site (PAG and SUA) by using the FFT band-pass filter analysis in the ULF range (0.001Hz - 0.0083Hz). Further on, a statistical analysis based on a standardized random variable equation was applied for the two particular cases: a) the assessment of the singularity for anomalous signal, related to the Mw6.4earthquake, observed on the daily mean distributions of the BPOL*(PAG) and BPOL*(SUA); b) the differentiation of the transient local anomalies associated with Mw6.4earthquake from the internal and external parts of the geomagnetic field, taking Geomagnetic Observatory (SUA) as reference, and the result is presented as daily mean distribution of the BPOL*(PAG-SUA). Finally, on the BPOL*(PAG-SUA) time series, carried out on the interval 1-30 November 2019, a very clear anomaly of maximum greater than 2.5 SD was detected on November 22, what means a lead time of 4 days before the onset of Mw6.4earthquake. In consequence, all mentioned results could offer opportunities to develop new tools for early detection of geomagnetic anomalies related to major seismic events. 

How to cite: Stanica, D. and Stanica, D. A.: Possible correlation beteen the pre-seismic geomagnetic signal and the M6.4 earthquake generated in the coastal zone of Albania, on November 26, 2019 , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13795, https://doi.org/10.5194/egusphere-egu2020-13795, 2020

Comments on the presentation

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Presentation version 1 – uploaded on 20 Apr 2020
  • CC1: Comment on EGU2020-13795, Michael E. Contadakis, 09 May 2020

    The  Day of the EQ precursory diagnostic of the Magnetic field variation coincides with the day of  TEC EQ precursory diagnostic (TEC turbulence band frequency content) .(D1650- EGU2020-1444, fig 11).

    • AC1: Reply to CC1, Dumitru Stanica, 09 May 2020

      It is nice that with two different methodologies the results regarding the pre-seismic anomalous signals related to the Mw6.4 Albania earthquake are similar.

      Thus, we should continue such researches for earthquake precursors detection in the both country.   

      Best regards,

                                Dumitru Stanica and Armand Stanica

       

  • CC2: Comment on EGU2020-13795, Michael E. Contadakis, 09 May 2020

    Actualy this coincidence is very important since our observant ,The TEC chaotic logarithic power spectrum(b=-2) means that the Ionospheric disturbunce happent over the seismic area for which you observe the magnetic field disturbence a the ground at the same time, thus my dear Stanica we just observe the LAIC proccess.

    Best regards

    Michael 

    • AC2: Reply to CC2, Dumitru Stanica, 09 May 2020

      Dear Michael,

      The EMSEV and EGU 2020 meetings give us possibility to solve such problems. 

      In our institute we have near-real time monitoring platform able to carried out ULF geomagnetic precursors related to Vrancea zone (Romania), thus any time we can cooperate including satellite data.

      Best regards,

                            Dumitru 

  • CC3: Comment on EGU2020-13795, Dedalo Marchetti, 09 May 2020

    First congratulation for the very interesting work and presentation! I have a question for this presentation: Do you check the data of the SUA magnetometer doing the same analysis to check if the results are different or the magnetic intensity of the anomalies is slower than PAG, because it is far from epicenter?

    • AC3: Reply to CC3, Dumitru Stanica, 09 May 2020

      Dear Dedalo,

      Thank you very much for your kind remarks.

      We checked the data of SUA Observatory using the same analysis.

      We are looking for precursors not the amplitude of the magnetic field, so that in this paper a statistical analysis based on SRVE was applied to:

      - assess the singularity of the anomalous signal related to Mw6.4 Eq.;

      - differentiate the transient anomalies associated with Mw 6.4 Eq. from internal and external parts of the magnetic field taking SUA Observatory as refference;

      - obtaine the BPOL* (PAG-SUA)  time series on the interval 1-30 November 2019.

      - identify a precursor related to Mw6.4 earthquake.

       Regards,

                       Dumitru