UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2022-07-01 16:47

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Conference: Bucharest University Faculty of Physics 2019 Meeting


Section: Atmosphere and Earth Science; Environment Protection


Title:
Geomagnetic variations recorded at Muntele Roșu observatory and their possible explanations


Authors:
Andrei MIHAI(1,2), Iren Adelina MOLDOVAN(1), Victorin Emilian TOADER(1)


*
Affiliation:
1)National Institute for Earth Physics, Romania

2)University of Bucharest, Faculty of Physics, Romania


E-mail
mihai.a.andrei@gmail.com


Keywords:
geomagnetic variations, Vrancea zone, anomalies, By component, seismogenic zone.


Abstract:
The geomagnetic field measured in Vrancea zone can variate from multitude causes and the majority of variations are short-time and pregnant one, being represented by the variations of the external magnetic field. To better distinguish the lithospheric/crustal anomalies from external geomagnetic variations (geomagnetic storms), the datasets recorded at Muntele Rosu (MLR) located inside the seismogenic zone were compared with datasets recorded at Surlari (SUA) located at 100km away to the seismogenic area. So far anomalies show two patterns, anomalies which last between 2 weeks and one month and anomalies which last between 5 months and 8 months. The geomagnetic variations are visible only on By component (E-W component) and the anomalies morphology is represented mostly by V-shape for short anomalies and a step-type for long anomalies. The nature of these anomalies may be caused by the thermal processes localized at intermediate depth like mineralogical phase changes, thermal demagnetization of rocks due to high temperature and the dehydration of rocks. Vrancea zone could be affected by a mature delamination process of the lower lithosphere which generates a tectonic uplift in this area. Another possible explanation for these slow variations of By components could be represented by the tectonic stress accumulation which generates a very fine movement of the magnetometer(1).The next step of this study will be represented by the correlation of geomagnetic data with data sets from dedicated sensors which measures the fine movements of tectonic plates( GPS stations, inclinometers).


References:

(1)Toader, V.-E., Moldovan,I.-A., Ionescu, C.,Marmureanu, A.,PRECURSOR PHENOMENONS IN VRANCEA ZONE, EGU General Assembly 2018, 8 – 13 April, Viena, Austria

Acknowledgement:
This study was carried out within Nucleu Program 2019 supported by Ministry of Research and Innovation, project number PN19080102