Long-Memory and Fractal Traces in KHz-MHz Electromagnetic Time Series Prior to the ML=6.1, 12/6/2007 Lesvos, Greece Earthquake: Investigation through DFA and Time-Evolving Spectral Fractals
Received Date: Apr 04, 2018 / Accepted Date: Apr 16, 2018 / Published Date: Apr 24, 2018
This paper presents evidence of long-lasting and chaotic trends in one-month kHz-MHz electromagnetic disturbances collected prior to a ML=6.1 shallow earthquake (June 12, 2017, 12:28:38 GMT, 38.84° N/26.36° E, 12 km deep, 37.5 km SSE of Mytilene town, Lesvos island, Greece) recorded by a telemetric ground station (39.23° N/26.27° E) located only 44 km away from the earthquake's epicenter. All analyzed earthquake occurrences (4.0 ≤ ML< 6.1) formed tight groups in both time and space which is significant for the investigation. The analysis is implemented via detailed timeevolving sliding-window two-slope DFA and power-law analysis of 4096 samples per window allowing hidden, potentially precursory, pre-earthquake trends to emerge. The classical two-exponent DFA results support the aspect of possible pre-earthquake activity 10-12 days prior to the ML=6.1 earthquake, for the 3-10 kHz antennas (both EW-NS orientations) and the 41-46 MHz ones, by simultaneously presenting a sudden increase of a parameter calculated from the two DFA exponent data. The time evolution of the power-law fractal-analysis data indicates activity 12-13 prior to the event, however, only for the 3 kHz antennas. Hurst exponents calculated in various analysis segments indicate persistency during the main pre-earthquake activity as well as persistency-anti-persistency changes. Potential pre-seismic activity prior to two other earthquakes of ML=5.0 and ML=4.6 is investigated and discussed. The precursory activity of reported time-series is discussed.
Keywords: Fractals; DFA; Spectral fractal analysis; Fractal dimension; Radon in soil; Earthquakes
Citation: Nikolopoulos D, Panayiotis H, Ermioni P, Demetrios C, Constantinos N (2018) Long-Memory and Fractal Traces in KHz-MHz Electromagnetic Time Series Prior to the ML=6.1, 12/6/2007 Lesvos, Greece Earthquake: Investigation through DFA and Time-Evolving Spectral Fractals. J Earth Sci Clim Change 9: 465. Doi: 10.4172/2157-7617.1000465
Copyright: © 2018 Nikolopoulos D, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Select your language of interest to view the total content in your interested language
Share This Article
- Total views: 1032
- [From(publication date): 0-2018 - Sep 22, 2019]
- Breakdown by view type
- HTML page views: 962
- PDF downloads: 70