Geomagnetic induction studies in Scandinavia. II. Geomagnetic depth sounding, induction vectors and coast-effect

Main Article Content

A.G. Jones


In this paper an event of very favourable structure for induction purposes, which was observed by the Scandinavian magnetometer array, is discussed and analysed in detail. The responses derived, in both the time and frequency domains, display a large coast effect at all coastal stations, both on the sea coasts and on the Gulf of Bothnia. Two relatively large inland anomalies are also delineated. The more significant of the two, the Storavan anomaly, is apparent using all the analysis techniques employed, and may be associated with a remnant of the Svionian island arc system. The less dominant anomaly, in the vicinity of Mieron, has no obvious correlation with geology or tectonic formations, and appears to be polarisation sensitive - it is only energised by east-west magnetic fields. First approximation modelling of the coast effect observed by the northwestern stations illustrated that the responses are well satisfied by the conductivity contrast between sea and land. Finally, the validity of the derived induction vectors, and the possible effects of induction for source field studies, are discussed.

Google Scholar           ARK:



Article Details

How to Cite
Jones, A. (1981). Geomagnetic induction studies in Scandinavia. II. Geomagnetic depth sounding, induction vectors and coast-effect. Journal of Geophysics, 50(1), 23-36. Retrieved from


Alabi, A.O., Camfield, P.A., Gough, D.I. (1975) The north American central plains conductivity anomaly. Geophys. J. R. Astron. Soc. 43:815-834

Bannister, J.R., Gough, D.I. (1977) Development of a polar magnetic substorm: A two-dimensional magnetometer array study. Geophys. J. R. Astron. Soc. 51:75-90

Baumjohann, W., Kamide, Y. (1981) Joint two-dimensional observations of ground magnetic and ionospheric electric fields associated with auroral zone currents. 2. Three-dimensional current flow in the morning sector during substrom recovery. J. Geomagn. Geoelectr. (In press)

Baumjohann, W., Untiedt, J., Greenwald, R.A. (1980) Joint two-dimensional observations of ground magnetic and ionospheric electric fields associated with auroral zone currents. 1. Three-dimensional
current flows associated with a substorm-intensified eastward electrojet. J. Geophys. Res. 85:1963-1978

Beer, J.H. de, Gough, D.I. (1980) Conductive structures in southernmost Africa: a magnetometer array study. Geophys. J. R. Astron. Soc. 63:479-495

Bendat, J.S., Piersol, A.G. (1971) Random data: analysis and measurement procedures. Wiley-Interscience, New York

Born, J., Wolf, E. (1964) Principles of Optics. MacMillan, New York

Dosso, H.W. (1973) A review of analogue model studies of the coast effect. Phys. Earth Planet. Inter. 7:294-302

Fischer, G. (1979) Electromagnetic induction effects at an ocean coast. Proc. IEEE 67:1050-1060

Fischer, G., Schnegg, P.-A., Usadel, K.D. (1978) Electromagnetic response of an ocean coast model to E-polarisation induction. Geophys. J. R. Astron. Soc. 53:599-616

Fowler, R.A., Kotick, BJ., Elliot, R.D. (1967) Polarisation analysis of natural and artificially induced geomagnetic micropulsations. J. Geophys. Res. 72:2871-2883

Frazer, M.C. (1974) Geomagnetic sounding with arrays of magnetometers. Rev. Geophys. Space Phys. 12:401-420

Glal3meier, K.-H. (1980) Magnetometer array observations of a giant pulsation event. J. Geophys. 48:127-138

Goodman, N.R. (1965) Measurement of matrix frequency response functions and multiple coherence functions. AFFDL TR 65-56, Air Force Flight Dynamics Laboratory, Wright-Patterson AFB, Ohio, February

Gough, D.I. (1973a) The interpretation of magnetometer array studies. Geophys. J. R. Astron Soc. 35:85-98

Gough, D.I. (1973b) The geophysical significance of geomagnetic variation anomalies. Phys. Earth Planet. Inter. 7:379-388

Gough, D.I., Beer, J.H. de (1980) Source-field bias in geomagnetic transfer functions: A case history. J. Geomagn. Geoelectr. 32:471-482

Gough, D.I., Lilley, F.E.M., McElhinny, M.W. (1972) A polarisation-sensitive magnetic variation anomaly in south Australia. Nature 239:88-91

Gough, D.I., Reitzel, J.S. (1967) A portable three component magnetic variometer. J. Geomagn. Geoelectr. 19:203-215

Gustafsson, G., Baumjohann, W., Iversen, I. (1981) Multi-method observations and modelling of the three-dimensional currents associated with a very strong Ps 6 event. J. Geophys. 49:138-145

Hermance, J.F. (1973) Processing of magnetotelluric data. Phys. Earth Planet. Inter. 7:349-364

Jones, A.G. (1979) On the difference between polarisation and coherence. J. Geophys. 45:223-229

Jones, A.G. (1980) Geomagnetic Induction Studies in Scandinavia-I. Determination of the inductive response function from the magnetometer array data. J. Geophys. 48:181-194

Jones, A.G. (1981a) On the reduction of bias in response function estimation for hand-digitised data. Geophys. J.R. Astron. Soc. (In press)

Jones, A.G. (1981b) Comment on "Geomagnetic Depth Sounding by Induction Arrow Representation: A Review" by G.P. Gregori and L.J. Lanzerotti, Rev. Geophys. Space Phys. (In press)

Jones AG (1981c) On the electrical crust mantle structure in Fennosca~ di~: No Moho, and the Asthenosphere revealed? Geophys. J. R. Astron. Soc. (In press)

Kuppers, F., Post, H. (1981) A second generation Gough-Reitzel magnetometer. J. Geomagn. Geoelectr. 33:225-237

Kuppers, F., Untiedt, J., Baumjohann, W., Lange, K., Jones, A.G. (1979) A two-dimensional magnetometer array for ground-based observations of auroral zone electric currents during the International Magnetospheric Study (IMS). J. Geophys. 46:429-450

Lilley, F.E.M. (1975) Magnetometer array studies: A review of the mterpretation of observed fields. Phys. Earth Planet. Inter. 10:231-240

Mareschal, M. (1980) A modelling of some effects of the source field on the Z/H ratio evaluated at sub-auroral latitudes in the period range 15 to 60min. (Abstract) EOS, Trans. Am. Geophys. Union 61

Meissner, R. (1979) Fennoscandia - A short outline of its geodynamic development. GeoJournal 3.3:227-233

Mersmann, U., Baumjohann, W., Kuppers, F., Lange, K. (1979) Analysis of an eastward electrojet by means of upward continuation of ground-based magnetometer data. J. Geophys. 45:281-298

Opgenoorth, H.J., Pellinen, R.J., Maurer, H., Kuppers, F., He1kk1la, W.J., Kaila, K.U., Tanskanen, P. (1980) Ground-based observations of an onset of localised field-aligned currents during auroral breakup around magnetic midnight. J. Geophys. 48:101-115

Schmucker, U. (1970) Anomalies of geomagnetic variations in the southwestern United States. Bull. Scripps Inst. Oceanogr., Univ. Calif. Press 13

Schmucker, U. (1971) Interpretation of induction anomalies above nonuniform surface layers. Geophysics 36:156-165

Schmucker, U. (1973) Regional induction studies: a review of methods and results. Phys. Earth Planet. Inter. 7:365-378

Schmucker, U. (1980) Diskussionsbeitrag zu "Uber die Unterschiede zwischen verschiedenen Definitionen der Induktionspfeile", In: Protokoll Uber das Kolloquium "Elektromagnetische Tiefenforschung"
in Berlin. 31.3.-3.4.

Untiedt, J., Pellinen, R., Kuppers, F., Opgenoorth, H.J., Pelster, W.D., Baumjohann, W., Ranta, H., Kangas, J., Czechowsky, P., Heikkila, W.J. (1978) Observations of the initial development of an auroral and magnetic substorm at magnetic midnight. J. Geophys. 45:41-65