Investigation of geomagnetic field variations in search of seismo-electromagnetic emissions associated with earthquakes in subduction zone of Andaman-Nicobar, India

Abstract

The study of seismo-electromagnetic emissions has the potential to provide new insights into the physics of seismic activity and improve our ability to monitor and predict earthquakes and other geophysical events. In this study, we examine one year of ground based geomagnetic data during March-2019 to April − 2020 from the Andaman subduction zone for signatures related to lithospheric processes. We focus on anomalous signatures in the vertical component of geomagnetic field after removing the global and seasonal effect from the data. We have also scanned for corresponding signatures in the polarization ratios estimated from spectral density in ULF range. Over the duration of one year, we noted an 80% enhancement in polarisation ratios and 67% deviations in diurnal ratios average 18 days before of earthquake events. Apart this, the significant enhances in diurnal and polarization ratio are successfully correlated with 11 out of 14 earthquakes shows an approximately 78 percent success ratio of present study.