TITLE:
The Use of Geomagnetic Measurements to Study Local Tectonics: Case for the NE Part of the Adria-Eurasia Collisional Zone
AUTHORS:
Polona Pavlovčič-Prešeren, Rudi Čop, Miran Kuhar
KEYWORDS:
Geomagnetic Field, Adria-Eurasia Collisional Zone, PIA Observatory, Earthquake
JOURNAL NAME:
Open Journal of Earthquake Research,
Vol.9 No.2,
March
12,
2020
ABSTRACT: Determination of the correlation between the energy-density changes in geomagnetic field and seismic events is a challenging scientific topic that allows the study of local tectonics using magnetometers. The magnetised properties of the crustal field of the Earth change due to natural sources and/or human activities that affect the environment. The latter can be avoided by setting up observatories in “geomagnetically-quiet” locations, while the natural sources, which describe the combined effects due to changes in the core, lithosphere, external or electromagnetically induced field, cannot be easily eliminated. This research focused on the investigation of local changes in the geomagnetic field in relation to evidently significant local tectonics in the vicinity of the PIA (Piran, Slovenia) geomagnetic observatory. It is obvious that geomagnetic measurements from PIA contain much higher levels of noise compared to the surrounding magnetometers in Italy and Croatia. According to previous geodynamic studies, the position of the PIA observatory is specific, since it is located at an Adriatic microplate that collides under the Eurasian plate. At this point it can be assumed that the reason for high-level noise in geomagnetic observations is due to the still ongoing Adria-Eurasia collisional process. Furthermore, the study of the earthquake on 1 November 2015 with a magnitude of 4.2 and its epicentre 150 km from PIA showed the correlation between higher energy density of the Earth’s magnetic field and the earthquake occurrence. From the results acquired by the computational strategy described in the research, it is obvious that, as expected, a few days prior and after the earthquake higher Earth’s magnetic field indicated some significant changes in the local geomagnetic field that might occur due to the increased stress in the Earth’s crust in the north-eastern part of the Adria-Eurasia collisional zone.