Journal : Acta Geophysica
Article : On the influence of DC railway noise on variation data from Belsk and Lviv geomagnetic observatories

Authors :
Vitkulin, A. V.
Institute of Volcanology and Seismology, Far East Branch, Russian Academy of Sciences, Petropavlovsk-Kamchatski, Russia,,
Semenov, V. Y.
Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland,,
Majewski, E.
Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland,,
Nenovski, P.
National Institute for Geophysics, Geodesy and Geography, Sofia, Bulgaria,,
Sayil, N.
Karadeniz Technical University, Engineering Faculty, Department of Geophysics, Trabzon, Turkey,,
Nguyen, N. T.
Institute of Marine Geology and Geophysics, Vietnam Academy of Science and Technology, Hanoi, Vietnam,,
Neska, A.
Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland,,
Abstract : Geomagnetic variation data from the observatories in Belsk (BEL, Poland) and Lviv (LVV, Ukraine) significantly suffer from disturbances caused by direct current (DC) electric railways. The aim of this study is to quantify the impact of these disturbances on quantities derived from such data, as the K index of magnetic activity and the induction arrow used in the geomagnetic deep sounding method to indicate lateral contrasts of elec- tric conductivity in the solid earth. Therefore, undisturbed data have been reconstructed by means of a frequency-domain transfer function that relates the horizontal magnetic field components of the observatory to the ones synchronously recorded at a noise-free reference station. The comparison of the K index derived from original and reconstructed data shows an increase of quiet time segments by 29 per cent for LVV and by 14 per cent for BEL due to our noise removal procedure. Furthermore, the distribution of the corrected K indices agrees well with the one from the Niemegk observatory in Germany

Keywords : geomagnetic observations, DC railway noise, induction arrows, K index,
Publishing house : Instytut Geofizyki PAN
Publication date : 2013
Number : Vol. 61, no. 2
Page : 385 – 403

: Bartels, J., N.H. Heck, and H.F. Johnston (1939), The three-hour-range index measuring geomagnetic activity, Terr. Magn. Atmos. Electr. 44, 4, 411-454, DOI: 10.1029/TE044i004p00411.
Gamble, T.,W. Goubau, and J. Clarke (1979), Magnetotellurics with a remote magnetic reference, Geophysics 44, 1, 53-68, DOI: 10.1190/1.1440923.
Georgescu, P., J.-L. Le Mouël, and M. Mandea (2002), Electric and magnetic perturbations generated by D.C. electric railway, Geofizica 40, 69-82.
Jozwiak, W. (2011), Large-scale crustal conductivity pattern in Central Europe and its correlation to deep tectonic structures, Pure Appl. Geophys., DOI: 10.1007/s00024-011-0435-7.
Krainski,W. (1968), On geomagnetic activity and K indices (O aktywnosci geomagnetycznej i wskaznikach K), Acta Geophys. Pol. 16, 1, 57-69 (in Polish).
Larsen, J.C., R.L. Mackie, A. Manzella, A. Fiordelisi, and S. Rieven (1996), Robust smooth magnetotelluric transfer functions, Geophys. J. Int. 124, 3, 801-819, DOI: 10.1111/j.1365-246X.1996.tb05639.x.
Lowes, F. J. (2009),DCrailways and the magnetic fields they produce – the geomagnetic context, Earth Planets Space 61, i-xv.
Maule, C., P. Thejll, A. Neska, J. Matzka, L. Pedersen, and A. Nilsson (2009), Analyzing and correcting for contaminating magnetic fields at the Brorfelde geomagnetic observatory due to high voltage DC power lines, Earth Planets Space 61, 11, 1233-1241.
Neska, A. (2010), Subsurface conductivity obtained from DC railway signal propagation with a dipole model. In: O. Ritter and U. Weckmann (eds.), Proc. 23rd Schmucker-Weidelt-Colloquium for Electromagnetic Depth Research, Dtsch. Geophys. Ges., Potsdam, Germany, 244-251.
Neska, A., A. Schäfer, L. Houpt, H. Brasse, and EMTESZ Working Group (2008), From Precambrian to Variscan basement: Magnetotellurics in the region of NWPoland, NE Germany, and south Sweden across the Baltic Sea. In: O. Ritter and H. Brasse (eds.), Protokoll zum 22. Kolloquium Elektromagnetische Tiefenforschung, Dtsch. Geophys. Ges., Potsdam, Germany, 151-163.
Nowozynski, K., T. Ernst, and J. Jankowski (1991), Adaptive smoothing method for computer derivation of K-indices, Geophys. J. Int. 104, 1, 85-93, DOI: 10.1111/j.1365-246X.1991.tb02495.x.
Oettinger, G., V. Haak, and J. Larsen (2001), Noise reduction in magnetotelluric timeseries with a new signal-noise separation method and its application to a field experiment in the Saxonian Granulite Massif, Geophys. J. Int. 146, 3, 659-669, DOI: 10.1046/j.1365-246X.2001.00473.x.
Pirjola, R., L. Newitt, D. Boteler, L. Trichtchenko, P. Fernberg, L. McKee, D. Danskin, and G.J. van Beck (2007), Modelling the disturbance caused by a dc-electrified railway to geomagnetic measurements, Earth Planets Space 59, 943-949.
Schäfer, A., L. Houpt, H. Brasse, N. Hoffmann, and EMTESZ Working Group (2011), The North German Conductivity Anomaly revisited, Geophys. J. Int. 187, 1, 85-98, DOI: 10.1111/j.1365-246X.2011.05145.x.
Schmucker, U. (1984), EM Übertragungsfunktionen aus Beobachtungen mit mehreren gleichzeitig registrierenden Stationen. In: 10. Kolloquium Elektromagnetische Tiefenforschung, Grafrath in Oberbayern, 35-36 (in German).
Sizow, Y.P. (1977), Instrukcija po sostawleniju mesjatchnogo obzora sostojanija magnitnogo polja zemli, Institute of Earth Magnetism, the Ionosphere, and Radio Wave Propagation, Academy of Sciences USSR, Moscow (in Russian).
Tokumoto, T., and S. Tsunomura (1984), Calculation of magnetic field disturbance produced by electric railway, Mem. Kakioka Magn. Obs. 20, 2, 33-44 (original in Japanese, English translation available).
*Wiese, H. (1962), Geomagnetische Tiefentellurik Teil II: Die Streichrichtung der Untergrundstrukturen des elektrischen Widerstandes, erschlossen aus geomagnetischen Variationen, Pure Appl Geophys. 52, 1, 83-103, DOI: 10.1007/BF01996002.
Yanagihara, K. (1977), Magnetic field disturbance produced by electric railway, Mem. Kakioka Magn. Obs. 38, 1, 17-34.
Qute : Vitkulin, A. V. ,Semenov, V. Y. ,Majewski, E. ,Nenovski, P. ,Sayil, N. ,Nguyen, N. T. ,Neska, A. ,Neska, A. , On the influence of DC railway noise on variation data from Belsk and Lviv geomagnetic observatories. Acta Geophysica Vol. 61, no. 2/2013