Henryk Marcak

Aiding of the GPR method by other measurement techniques for liquid contamination detection

In the paper the selected results of measurements carried out for detection of two types of liquid contamination are presented. The authors made detection of contamination, which very often leaks to the ground, i.e. the low-conductivity hydrocarbon contamination and the high-conductivity chemical solution. Depending of the site and the type of contamination different measurement techniques were used: the GPR, the atmogeochemical measurement, the laboratory analysis, the resistivity imaging survey and the conductometry. A brief discussion about possibilities of liquid contamination detection using electrical and electromagnetic techniques is presented in the paper.

The use of GPR attributes to map a weak zone in a river dike

Dike leakage can be the result of a rupture and the formation of loose zones which are not able to stand the water pressure during flooding. Loose zones are significantly more saturated when it rains and floods than the undamaged portion of the dike. Due to the increased water in loose zones, their electrical properties are changed, particularly dielectric permittivity. As a result, these zones have a different ground-penetrating radar (GPR) wave reflection coefficient and are a source of wave diffraction. The interpretation of GPR measurements carried out on a leaking dike during a flood event in Poland is presented in this paper. The GPR attributes, such as an instantaneous phase, envelope, instantaneous frequency averaged over time and traces, have been analysed in the paper the interpretative tools. Also, the averaged spectrum (spectrum calculated from averaged traces) and moving spectrum (averaged spectrum calculated in windows moving along the traces), as well as the phase spectrum, of recorded GPR data were analysed as indicators of the existence of the deterioration of parts of the dike. As shown in the paper, the use of GPR signals attributes and spectra in the interpretation of field measurements can increase the available information about the structure of the dike by highlighting some of the physical properties of its construction.

Cycles in mining seismicity

Stochastic models of self-organized criticality and intermittent criticality are used to describe the structure of seismic catalogs. The intermittent models introduce three phases of the seismic cycle: increase in seismic energy, seismic relaxation, and seismic quiescence after the final relaxation. In this paper, seismic mining catalogs from a deep copper mine are searched to find these three phases of the seismic cycle. In spite of the differences between the seismic records from earthquakes and the building of stresses in the mine, the cycles can be estimated in mining seismicity.