Earthquake precursory signatures in electromagnetic radiation measurements in terms of day-to-day fractal spectral exponent variation: analysis of the eastern Aegean 13/04/2017–20/07/2017 seismic activity
The recent seismic activity in the eastern Aegean Sea, foregrounded by two major ( M L = 6.1 and M L = 6.2) earthquakes occurring near Lesvos and Kos islands, respectively, is investigated in this work. Electromagnetic radiation measurements across different frequency bands and antenna orientation...
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Published in | Journal of seismology Vol. 22; no. 6; pp. 1499 - 1513 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Dordrecht
Springer Netherlands
01.11.2018
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The recent seismic activity in the eastern Aegean Sea, foregrounded by two major (
M
L
= 6.1 and
M
L
= 6.2) earthquakes occurring near Lesvos and Kos islands, respectively, is investigated in this work. Electromagnetic radiation measurements across different frequency bands and antenna orientations from a monitoring station in Agia Paraskevi, Lesvos Island, are analysed in order to reveal earthquake precursory signatures hidden in the electromagnetic data sequence. A straightforward, data-driven approach is employed in which day-to-day variations of the fractal characteristics of the measurements are adaptively monitored via a fractal spectral exponent similarity measure. The evolution of the fractal day-to-day variation in a 99-day period, which includes the two major earthquakes, shows a sustained, sudden increase lasting 1 to 4 days before every earthquake cluster of
M
L
= 4.0 and above. Most importantly, this day-to-day variation subsides shortly after and remains relatively low during the absence of earthquakes, thus alleviating the emergence of false alarms. |
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ISSN: | 1383-4649 1573-157X |
DOI: | 10.1007/s10950-018-9781-6 |