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Patterns of Seismo-Electromagnetic Signatures of Moderate Earthquakes in Diverse Tectonic Settings.

Arora K, Prajapati R.

JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA

https://doi.org/10.17491/jgsi/2025/174166 

The analysis of geomagnetic data from active region of the Andaman-Nicobar subduction zone and an aseismic peninsular shield of the Indian subcontinent shows seismo - electromagnetic signatures in Diurnal and Polarization ratio. Overall, data from the Nicobar subduction region where moderate earthquakes are frequent, record large number of prominent PR and less conspicuous DR anomalies. On the other hand, the geomagnetic data from the Eastern Dharwar craton produce single DR anomaly of eight days’ duration and a few weak PR anomalies. Thus the distinct pattern in terms of SEM signatures indicate the distinct seismic characteristics of the two regions as well as possible electro kinetic and motional induction mechanisms contribute to the signatures of the subduction zone earthquakes.

Panel shows spatial location of earthquakes with structural feature of (Left) Campbell-Bay (Right) Peninsular India.

Polarization ratio anomalies of geomagnetic data in (a) Hyderabad (HYB) and (c) Campbell-Bay region (CBY) with earthquakes sequence (b) HYB and (d) CBY respectively.

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