Two-dimensional radiomagnetotelluric investigation of industrial and domestic waste sites in Germany

Radiomagnetotelluric surveys were carried out on two different waste sites in order to map them and to detect the surrounding hosts. One was filled with industrial waste and the other with household refuse. Both had been recultivated. Powerful military and civilian radiostations (10-300 kHz) located parallel and perpendicular to the strike direction of both waste sites served as transmitters. Hence, apparent resistivity and phase data were observed for several selected frequencies. Using this field setup, the data were associated to the E- and B-polarisation directions of the magnetotelluric field. The lateral borders of both waste sites are located accurately in the field. They are characterized by strongly decreasing apparent resistivities observed at nearly all frequencies at the border between the waste site and the undisturbed geology. The data were quantitatively interpreted by conductivity models using a 2D inversion algorithm. The derived 2D conductivity models give information about the vertical extent of the studied waste sites and about the structure of the surrounding hosts. (C) 2000 Elsevier Science B.V. All rights reserved.