Tsunami effects on the Z component of the geomagnetic field

TL;DR

This study investigates how tsunamis influence the vertical component of the Earth's geomagnetic field using wavelet analysis on data from multiple events, revealing localized transient effects linked to tsunami activity.

Contribution

It demonstrates the application of discrete wavelet transform to detect and analyze tsunami-induced geomagnetic variations, providing a new method for tsunami monitoring via geomagnetic data.

Findings

Detected localized geomagnetic variations during tsunamis

Identified initial phase and maximum height timing of tsunamis

Wavelet analysis effectively characterizes tsunami effects

Abstract

The vertical component (Z) of the geomagnetic field observed by ground-based observatories of the INTERMAGNET network has been used to analyze the effects of the movement of electrically conducting sea water through the geomagnetic field due to a propagation of a tsumani. The purpose of this work is to study the geomagnetic variations induced by the tsunamis occurred at 26 December, 2004, 27 February, 2010 and 11 March, 2011. For each case study, we selected four magnetic stations belonging to the INTERMAGNET programme that were influenced or more direct affected by the tsumani. To detect these disturbances in the geomagnetic data, the discrete wavelet technique have been used in four levels of decomposition. We were able to detect the localized behavior of the geomagnetic variations induced by the movement of electrically conducting sea-water through the geomagnetic field, i. e., the identification of transients related to the tsunamis. As well, using the minutely magnetogram data, it was able to localize the initial phase and time of the tsunami maximum height. The first interpretation of the results suggests that discrete wavelet transform can be used to characterize the tsumani effects on the geomagnetic field, but need further study.