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Detailed analysis of the geomagnetic ground survey performed in middle-northern Croatia over the time interval 2003–2005

  • Eugen VujićEmail author
  • Giuliana Verbanac
  • Vladis Vujnović
  • Antun Marki
Article

Abstract

During the time interval 2003–2005 a ground survey of the total magnetic field intensity in the middle-northern part of Croatia was performed, in order to get a detailed insight of the field distribution over the region. A special effort was done to understand the uncertainty and errors in data reduction, namely different amplitudes of the diurnal variations and different secular variations at the ground stations with respect to the observatories. For data reduction to epoch 2004.5 the total field recordings from AQU, FUR, NCK and THY geomagnetic observatories have been used. We estimate the mean determination error to be one order of magnitude smaller than the maximal reduction error. Multiple linear regression and the method of empirical orthogonal functions were applied on the ground survey and observatory time series. This allowed us to explain the correlations among them and the variance of the total field. Furthermore, we identified two sources of serious artificial disturbances caused by DC leakage: the tramway system of the capital and one railway station in neighbouring Slovenia. Also, we estimate the region free of these disturbances. The magnitude of one of them is estimated to be more than five nT at the distance of about 10 km.

Key words

ground survey data reduction geomagnetic observatory artificial disturbances 

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Copyright information

© Institute of Geophysics of the ASCR, v.v.i 2009

Authors and Affiliations

  • Eugen Vujić
    • 1
    Email author
  • Giuliana Verbanac
    • 1
  • Vladis Vujnović
    • 1
  • Antun Marki
    • 1
  1. 1.Faculty of SciencesUniversity of ZagrebZagrebCroatia

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