Methods for the Evaluation of the Stochastic Properties of the Ionosphere for Earthquake Prediction—Random Matrix Theory

Leontýna Břizová,Jan Kříž,Filip Studnička,Jan Šlégr

doi:10.3390/atmos10070413

Leontýna Břizová, Jan Kříž + Show 2 more

Open Access

https://doi.org/10.3390/atmos10070413

Copy DOI

Journal: Atmosphere	Publication Date: Jul 18, 2019
Citations: 2	License type: CC BY 4.0

Affiliation: University of Hradec Králové

Abstract

Seismo-ionospheric coupling is a field of great interest and is currently subject to rigorous study; using both ground and satellite data and many phenomenological features, the ionospheric precursors of earthquakes were identified. In this work, we present methods to study the stochastic properties of the lower ionosphere, derived from the data obtained with very low frequency (VLF) receivers at frequencies in the range of 19.6 to 37.5 kHz. Two main approaches are described: auto-correlation and random matrix theory treatments of amplitude time series data. It is shown that before shallow earthquakes with magnitudes greater than four, there are measurable changes that can be used in earthquake prediction. Although the exact form of the causal chain that leads to these changes are currently subject to diligent study, we believe that the investigations described herein are worth adding to the repertoire of ionospheric precursors.

Highlights

The complex chain of processes in the atmosphere, ionosphere, and magnetosphere before earthquakes result in precipitating particles producing ionization of the lower ionosphere
In a previous work [5], we described the link between the stochastic properties of the lower ionosphere and seismic activity
We describe a novel method for the study of the chaotic properties of the ionosphere, using random matrix theory for the first time in this field

Summary

Introduction

The complex chain of processes in the atmosphere, ionosphere, and magnetosphere before earthquakes result in precipitating particles producing ionization of the lower ionosphere. The ionization leads to an increase in the electron concentration in the D-region of the ionosphere, which is equivalent to lowering the ionosphere [1]. This lowering changes the condition of radio wave propagation in different frequency bands from VLF up to VHF. Several ionospheric precursors of earthquakes are currently under investigation (for details see [2] or [3]). The electromagnetic precursors of earthquakes (not limited to the VLF part of the electromagnetic spectrum) are discussed with case studies in a recent paper [4]

Methods

Results

Conclusion