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A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
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Normal seasonal variations for atmospheric radon concentration: a sinusoidal model
Koseki Hayashi1, Yumi Yasuoka1, Hiroyuki Nagahama2
1Kobe Pharmaceutical University, 4-19-1, Motoyamakitamachi, Higashinada-ku, Kobe 658-8558, Japan.
Journal of Environmental Radioactivity
|December 3, 2014
Summary
Scientists monitored atmospheric radon concentrations for five years to establish a baseline. This allowed them to identify anomalous radon variations preceding the 2011 Tohoku-Oki Earthquake, aiding in earthquake prediction research.
Area of Science:
- Geophysics
- Environmental Science
- Atmospheric Chemistry
Background:
- Anomalous atmospheric radon concentrations have been previously linked to earthquake activity.
- Establishing a baseline of normal radon levels is crucial for identifying significant pre-earthquake variations.
- Long-term, careful measurements are needed to differentiate normal fluctuations from potential seismic precursors.
Purpose of the Study:
- To establish a normal range of atmospheric radon concentrations over a five-year period (2003-2007).
- To compare normal radon data with data from the precursory period leading up to the 2011 Tohoku-Oki Earthquake.
- To develop a method for identifying anomalous radon variations as potential earthquake precursors.
Main Methods:
- Collected atmospheric radon concentration data from 2003 to March 2011.
- Modeled seasonal radon variations using a sinusoidal fit based on the normal period data (2003-2007).
- Accounted for atmospheric turbulence's effect on seasonal radon concentration patterns.
Main Results:
- A sinusoidal model was successfully established to represent normal seasonal variations in radon concentration.
- The amplitude of the sinusoidal model allowed for the estimation of normal radon variation ranges.
- Deviations from this established normal variation were observed in the precursory period.
Conclusions:
- The developed sinusoidal model effectively estimates normal radon concentration variations.
- This method provides a reliable approach to identifying anomalous radon readings that may precede seismic events.
- The findings contribute to the understanding of radon as a potential earthquake precursor.
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